WEST PALM BEACH, Fla. — Twelve months ago, Hunter Brown represented hope for a farm system without much of it. He appeared on all of the top-100 prospect lists when no other Astro could crack them. His strikeout numbers and staggering success in the minor leagues led to aspirations that he could morph into a homegrown ace.

Hype billed Brown as a finished product. His first full major-league season showed the folly in such a presumption. Brown battled bad luck, backbreaking innings and big-league hitters who solved an arsenal with too many similar pitches — pitfalls many pitchers his age must power through.

Brown did the best he could. He authored a successful rookie season, even if it did not match the outsized expectations that enveloped him. Inexperience is a fine defense of his second-half decline, but it will disappear this season. Brown is now a bona fide big leaguer, one growing in importance as Houston’s rotation depth continues to dwindle.

“We need him to step up and show that he can be a strong, foundational starter that can get deep in games,” pitching coach Josh Miller said on Monday. “I think we’re expecting him to take a step forward and we need it.”

Brown still boasts the same arsenal that attracted crowds to his spring training bullpen sessions and live batting practices as a prospect. Harnessing it for a full major-league season is the next step in his evolution.

Hunter Brown, Elevated 97mph ⛽️ pic.twitter.com/fKpwi0C8hP

— Rob Friedman (@PitchingNinja) September 24, 2023

Never has it been more crucial for that development to accelerate. The 25-year-old will open the season as the third-longest tenured starter in a rotation that hopes to contend for a World Series — a chance to actualize his aforementioned hype while keeping this club afloat amid its rash of injuries.

“He can become a No. 1 one day,” manager Joe Espada said on Monday. “We all feel that. But he’s going to have to take that next step — maturing, controlling emotions, all that stuff that you want to see out of a young pitcher turning that corner and becoming more aware of the things you need to do to be more consistent.”

Doing it would benefit both Brown and the ballclub. He is a logical candidate for the sort of pre-arbitration contract extension general manager Dana Brown said earlier this spring he hopes to give.

A step forward in Hunter Brown’s sophomore season would only increase his value. The right-hander recently switched his representation from Wasserman to Ballengee Group, but it’s unclear if there has been any traction toward a long-term pact this spring.

It’s almost immaterial if there has been. Piecing together Houston’s season-opening rotation is the club’s greatest concern and Monday made it more difficult. Imaging on José Urquidy’s injured elbow revealed a forearm muscle strain, Espada said on Monday morning.

Forearm strains are often precursors for damage to the ulnar collateral ligament, which if torn would require Tommy John surgery. When asked on Monday, Espada said he did not know the status of Urquidy’s UCL.

Other than to rule him out for the beginning of the season, Espada did not offer a timetable for Urquidy’s return. Players with forearm strains often aren’t rushed back, so an extended absence is almost expected.

Pair it with Justin Verlander’s shoulder inflammation and Houston may begin the season with seven healthy starters on the 40-man roster. Two of them, Ronel Blanco and Shawn Dubin, have combined to throw 67 1/3 major-league innings. Dubin has yet to face hitters in spring training.

Houston remains engaged in the starting pitching market, but even if the club signs Blake Snell or another available free agent, it does not decrease the responsibility Brown will bear. Any outside addition will require time to build up and acclimate to a new organizational infrastructure, meaning Brown should slot third behind Framber Valdez and Cristian Javier in the Astros’ rotation when camp concludes.

Brown made 29 starts and two relief appearances last season, totaling 155 2/3 innings. No American League rookie pitcher threw more. A 4.37 FIP and .330 batting average on balls in play hinted some poor luck contributed to Brown’s 5.09 ERA, but a lack of swing-and-miss only exacerbated it.

Opponents whiffed at a 24.8 percent clip against Brown last season and chased outside the strike zone 27.5 percent of the time. Both benchmarks are at or below the major-league average. Brown’s curveball generated most of his swing-and-miss while serving as his most effective putaway pitch, but it is far more effective against left-handed hitters.

Without a true putaway pitch, right-handed hitters slashed .276/.341/.499 against Brown. Most of them were able to sit on something hard — be it a four-seam fastball that averaged 95.7 mph or a cutter/slider hybrid that sat at 91.7 mph — and find success. Righties slugged .550 against Brown’s four-seamer and hit .320 against the hybrid.

This winter, Brown developed a new, slower slider to get right-handed hitters off of those pitches. He threw 14 sliders during Monday’s start against the Miami Marlins and averaged 86.7 mph — the sort of disparity that should allow for better deception and, perhaps, more swings and misses.

“I think the timing of it is probably the best (it’s been),” Brown said. “It’s not really going to be a pitch that I rely a whole ton on the movement — it’s not a big sweeper like some guys throw. Kind of mixing that in with the cutter, curveball and changeup, it’s going to be a good look with that. It’s probably not perfect yet — I don’t know if I’m going to get there right away — but it’s something that’s a work in progress and I like the steps I’m taking so far.”

Fewer balls in play mean fewer chances for poor luck and long innings. Brown finished six innings in just four of his 12 starts after the All-Star break, succumbing to big innings and an inability to stop adverse situations from spiraling. His inability to hold baserunners made it worse, prompting Brown to spend most of this spring working on varying his times to home plate and trying a slide step in his delivery — intricacies that weren’t a priority in the minor leagues.

“We saw some typical youth emotions happen last year which allowed some of those big innings to spiral on him,” Miller said. “Frustrations can happen. He’s good at keeping it internal — he’s not going to be visibly yelling at umpires or his teammates or spiking the rosin bag or cursing or anything like that out on the field.”

Inexperience is no longer an excuse for a pitcher who is now indispensable.

(Photo of Hunter Brown: Jim Rassol / USA Today)