Lakers remind us teams can undo trades; two-way upgrades and scouting Spurs' Stephon Castle

Wait, you can undo a trade in the NBA?

Yes, actually, you can. Boom, Ctrl-Z. Just like that.

It rarely happens, for fairly obvious reasons. Execs are not going to spend all this time negotiating a deal (you have no idea how excruciating it can be to get from the 5-yard line to the end zone on these) and then just go “Psyche!” three days later.

But every so often, it happens. The Lakers’ unwinding of their trade deadline swap for Mark Williams is the latest, rare example of a team exiting a trade because of a failed physical.

Late Wednesday night, L.A. had agreed to send Dalton Knecht, Cam Reddish, a 2030 pick swap and a 2031 first-round pick to Charlotte for Williams ahead of Thursday’s trade deadline. By Saturday, when Williams wasn’t yet active for the Lakers’ game against Indiana, it was obvious something might be up. Later that evening, the Lakers canceled the trade.

Here’s the deal: In the NBA a trade isn’t complete until both teams sign off that the players have reported to their new teams and completed and passed their physicals. Teams often agree to waive this requirement for salary-dump trades where the players are secondary to the accounting, but never for a basketball-driven move like this one.

The NBA’s collective bargaining agreement (CBA) gives players 48 hours to report and submit to a physical. Then the team has another 24 hours to approve the physical. That time can also be extended by agreement of all sides in the trade. However, time is usually of the essence in trades, as none of the players in the deal can participate in a game until all of them pass.

So what do we mean by “pass,” exactly? Well, we’re getting into murky territory. This is an important and underrated point: Technically, a team can fail a player’s physical for any reason at all. A hangnail. A droopy eyelid. Halitosis. Anything.

Thus, in past instances where this has happened, many around the league have wondered if “cold feet” was the actual medical issue, rather than a newly discovered physical problem with the player. If we’re being very technical, in fact, flunking the physical is an act of omission and not an act of commission — the team is simply failing to approve the final step on the trade, and thus preventing its completion.

Actually, this was not the first instance of a physical resulting in a trade alteration at the 2025 deadline. The difference however, is that the other instance still ended with a trade going through: Philadelphia agreed to send Dallas a future second-round pick in addition to their previously negotiated trade, when the Mavs felt Caleb Martin’s hip injury was worse than they originally believed.

The Lakers and Hornets didn’t have that option, however, because after the 3 p.m. EST Thursday trade deadline, no trade modifications are allowed. In contrast, Dallas and Philly had agreed to their deal on Tuesday and completed Martin’s physical early enough that they could renegotiate terms just before the deadline buzzer.

That policy is one of the hidden risks of last-minute shopping: The Lakers’ only option was to either complete the trade as agreed, or blow it up. As I noted above, whether they unwound the trade because they didn’t like the imaging on Williams’ knee or just didn’t like the defensive clips that people were posting on social media, is almost irrelevant. The end-game is the same: An incredible sliding-doors moment.

What would the Lakers have done this season with Williams? What would their future be like? While this type of speculation is possible with any player-team combo, this one feels more real because they had an agreed-upon trade. We will always have that parallel comparison point over the next few years.

And because of that, it evokes memories of two other great sliding doors moments in NBA history that involve flunked physicals: Tyson Chandler and Sean Elliott.

At the 2009 deadline, the Oklahoma City Thunder had a deal ready to go that would send Chris Wilcox, Joe Smith and the draft rights to DeVon Hardin to New Orleans for Tyson Chandler. However, the Thunder rescinded the deal due to concerns with Chandler’s toe.

Whatever the issue was with the toe, he went on to play 11 more seasons, and started at center for the Dallas team that beat the Thunder in the 2011 Western Conference finals en route to the championship. Meanwhile, those Oklahoma City teams never found the answer at center — trading for Kendrick Perkins and supplementing him with other fringe rotation players until drafting Steven Adams in 2014. Can you imagine if they’d had Chandler running with Russell Westbrook, James Harden, Kevin Durant and Serge Ibaka?

Going further in the way-back machine, in February 1994, the Houston Rockets and Detroit Pistons had a deal ready to go that would send Sean Elliott to the Rockets for forwards Robert Horry and Matt Bullard and two second-rounders.

Elliott flunked his physical in Houston because of a kidney condition that eventually required a transplant, although he played seven more seasons, made the 1996 All-Star team and started for the Spurs championship team in 1999. Horry, meanwhile, started on the Rockets’ champions in 1994 and 1995 and, ironically, also ended up winning two rings in San Antonio. This one is fascinating to ponder because it impacts so many champions of that era, including the three Lakers champions Horry played on from 2000 to 2002. Do any of his seven championships happen if he goes to the Pistons in 1994? Does Horry’s presence swing the 2005 finals that the Spurs won over Detroit in seven?

Will the Williams non-deal fall into that category … or will it be more along the lines of the Donatas Motiejūnas trade between Houston and Detroit that was rescinded in 2015? (Yeah, not a lot of long-term reverberations from that one.) Only time will tell.

For now, Williams goes back to Charlotte, and Knecht and Reddish go back to L.A., each knowing their team tried to trade them. Awkwaaaaard. The Lakers also get their picks back and, perhaps, a chance to do something a bit more emphatic with them in the offseason.

Theoretically, they could even trade for Williams again this summer on different terms, although I’m not sure the Hornets will be returning their calls. (One of the ancillary costs of nuking a trade is that other teams become less willing to do business with you, especially the one you just burned.)

In the short term, L.A. is left high and dry in the middle, which is why they dealt for Williams in the first place. (And why they likely thought long and hard before rescinding it.) They have to go through the rest of the current season with a replacement-level combo of Jaxson Hayes and Christian Wood as their centers, which seems suboptimal. The Lakers might be able to find a big man in the buyout market, but the trade also put them back to 15 players, so the Lakers would need to waive somebody. Also, this year’s buyout market seems pretty dry at the center spot.

Charlotte, meanwhile, now faces the prospect of either extending Williams this summer or once again turning to the trade market. Any deal with him is complicated by the fact that the Lakers flunked his physical, which combined with Williams’ injury history will make other partners skittish.

All because of an odd, little-used provision of the NBA trade rules that allows teams to zap a trade, just like that.

Cap Geekery: The call-up list

With some of the roster expansion rules of the last decade, a front office’s work is no longer done at the trade deadline. While the buyout market has always been a feature of late February — any player waived by March 1 is eligible for the playoffs — there is a new, recent wrinkle now that each team has three two-ways: The call-up.

While the league has 90 two-way spots, these players are not eligible for the postseason, so for the 20 teams making it to the Play-In or further, they’d need any two-way promoted to the active roster by the time the end of the season. In addition several two-ways have used up so many of their allotted 50 games of active roster service that they’re in danger of becoming ineligible until promoted. (This actually happened a few times in 2023-24, most notably with a multi-week ineligible stint for Atlanta’s Trent Forrest).

With that in mind, I thought I’d take a look at the dozen two-ways most likely to get promoted between now and the end of the season. With apologies, since I’m doing this late enough that a few of them already signed their deals.

1. Ajay Mitchell, PG, Oklahoma City (signed) — The 38th pick in the draft has been a rotation player for the team with the league’s best record and recently agreed to a reported two-year, $6 million deal to move up to the main roster. While terms haven’t been disclosed, I wouldn’t be shocked if there was a second-year team option that allows the Thunder to decline the option this summer and re-sign him to a longer deal. They were limited to just two years (i.e, the remainder of this season plus one more) because he was signed via the room exception.
2. Justin Edwards, SF, Philadelphia (signed) — The undrafted Edwards has been a revelation of late; I wrote about him last week. He reportedly signed a two-year contract with a team option for next year, for the same reasons as Mitchell above. Philadelphia only had a minimum deal to offer since it was out of exception money.
3. Justin Champagnie, SF, Washington — It’s surprising that a team this bad would have a two-way this good. Champagnie has started 14 games and is pushing for the team lead in PER. Playoff eligibility isn’t a real concern for the Wizards, but they likely want to sign Champagnie to have him back on a favorable deal next season.
4. Jared Butler, PG, Philadelphia — A Wizard until the trade deadline, he was the rare two-way to be involved in a trade and is now with the Sixers. Philly might not promote him immediately given that they just did so with Edwards and are trying to make a playoff push, but Butler’s 17.8 PER in 362 minutes in Washington pretty much screams roster player.
5. Jalen Clark, SG, Minnesota — Surprise! From nowhere, Clark has rather suddenly emerged as an important bench spark for the Wolves with his defense and activity. The 53rd pick in 2023 sat out last season to rehab a torn Achilles, but he’d be unlikely to sign a deal until the final week of the season give Minnesota’s tax position.
6. Brandon Boston Jr., SF, New Orleans — Boston will need to move up soon since he’s almost out of active days. The Pelicans have an open roster spot and room below the tax line to add him, and given that he’s been a solid back-end rotation player (12.5 PER, 35 percent from 3 in 993 minutes) they should want him on a team-friendly deal going into next year.
7. Jordan Miller, SG/SF, LA Clippers — Miller is on the verge of running out of two-way days and has done a solid job in his minutes, but the Clippers will add Ben Simmons into their 15th roster spot once he clears waivers on Monday. That may mean he has to wait for another roster move before he moves up to the varsity for good.
8. Ryan Rollins, PG/SG Milwaukee — Rollins has barged into the back end of the Milwaukee rotation by showing he can make an impact at the defensive end, but the Bucks’ tax issues mean Milwaukee likely will drag its feet on signing him with their last roster spot until he runs out of two-way days.
9. Quinten Post, C, Golden State (signed) — Golden State promoted the 52nd pick in the draft after he made six recent starts; the Warriors were down to 11 players following the Jimmy Butler trade and by rule had to do something. Post is a floor-spacing big who opens things up for the Warriors whirring cuts, but a defensive liability. With three more roster spots to fill, don’t be surprised if his fellow 2-way Pat Spencer also joins the active roster.two
10. Moussa Diabaté, C, Charlotte (signed) — Charlotte had an open roster once the Williams trade was rescinded and immediately acted to ink Diabaté, who has been an energetic force on the glass all year. His 17.0 percent offensive Rebound Rate ranks sixth in the league among players with at least 500 minutes played.
11. Jamison Battle, SF Toronto (signed) — Toronto promoted Battle into its empty roster spot just after the trade deadline, using their some of the Raptors’ leftover midlevel exception money to ink a three-year deal. The undrafted Battle has been a solid floor spacer, shooting 42.9 percent from 3.
12. Quenton Jackson, SG, Indiana — Jackson is probably the most interesting puzzle on this list; he’s better than a lot of guys listed above him here, but his pathway to a roster spot is unclear since the playoff-bound Pacers have a full roster. Jackson did a solid job in six emergency starts earlier this year when Indiana had a roster shortage, and has defensive energy and overall stat line both suggest he’s worth of a 15-man roster spot. Whether than can happened before the end of the year in Indy, alas, is an open question.

Rookie of the week: Stephon Castle, PG/SG, Spurs

(Note: This section won’t necessarily profile the best rookie of the week. Just the one I’ve been watching.)

San Antonio’s rookie guard has been a hot topic over the last two weeks. First, it was for the possibility that he might be included as part of an outgoing package to Sacramento for All-Star guard De’Aaron Fox. Then, when he wasn’t traded, the story turned to his a potential long-term backcourt partner with Fox.

Meanwhile, Castle has also stepped up his play of late, averaging 18.4 points over his last eight games. In a rookie crop where nobody has stood out, he has emerged as the closest thing to a favorite to win Rookie of the Year. Castle can be wild at times and his shooting is a clear work in progress (28.2 percent from 3), but his transition play and ability to attack off the dribble bode well for a potentially larger role as on on-ball creator.

I was in San Antonio last week to see him play twice, including a 20-point, eight-rebound, six-assist showing in a blowout win over Milwaukee. While that was one of his better games, there has been a Jekyll-and-Hyde aspect to his play for much of the season. An unusually high Usage Rate for a rookie (24.0 percent) likely contributes.

“It’s hard to tell young people to be uber-aggressive, and then be perfect on decision-making,” Spurs acting head coach Mitch Johnson said after that Milwaukee game. “He’s an extremely aggressive player that can do so many different things, [but] he may crash the car every now and then.”

After seeing him twice in person and going back through the tape, it’s easy to see both sides of the Castle debate. His best plays are up there with anyone’s from this class.

For instance, look at this ridiculous Smitty he pull off against Orlando on Saturday:

On the other hand, Castle probably needs his jump shot to come around to help weaponize his off-the-dribble game. Teams go under screens against him with impunity, leaving little advantage gained while they dare him to shoot. Opponents have even dared to guard him with centers, although he burned Milwaukee when they tried that in the second half of the game I attended.

The other reason he needs the jumper, though, is because he doesn’t have the kind of explosion that would make him an elite finisher in traffic. Castle is fast and aggressive, especially in transition, and his penetration can create easy chances for teammates.

However, too many times he goes up against length at the rim and either can’t blast off vertically to finish or can only do so via a difficult contested shot, like here:

That would be less of an issue if he was more a pull-up threat, but Castle’s floater and mid-range game both could use work, as well. Half of his 2s are outside the restricted area and he’s only made a third of them. That’s not gonna work. If he isn’t going to be elite in the rim area, there has to be some other comfort zone on the court for him where he’s dangerous.

For now, the intensity of the on-the-job training will likely shift with Fox’s addition; there should be fewer on-ball opportunities. (Although that didn’t stop Castle from scoring a season-high 33 in Fox’s second game). Regardless, his arrow is trending upward as we head into the final third of the season, and if the shooting can just get to league average the 20-year-old is likely a long-term piece in south Texas.

“I think you see him learning on the job and he’s making the same mistake less,” Johnson said. “That’s all you can ask for in a kid with the amount of effort and competitiveness he plays with, you live with a lot of that stuff.”

Required reading

• Why this year’s deadline was all about 2026 — and Wembanyama
• NBA buyout market tiers: 35 players to watch now

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(Photo of Mark Williams: Kent Smith / NBAE via Getty Images)