The Houston Astros are placing Cristian Javier on the injured list with a neck problem, manager Joe Espada told reporters Sunday morning, prolonging an avalanche of injuries ravaging the team’s rotation.

Javier will be the sixth Houston starter to spend time on the IL this season and joins four projected members of the team’s rotation currently sidelined.

Ace Justin Verlander returned from the IL on Friday, throwing six innings of two-run ball in his season debut against the Washington Nationals.

Javier was scheduled to start Sunday’s series finale at Nationals Park, but got scratched with what the Astros described as “neck discomfort.” Hunter Brown, on regular rest, started in place of Javier.

Javier had emerged as one of Houston’s most stabilizing starters during an otherwise dreadful April. He surrendered four earned runs across his first four starts, striking out 18 in 23 1/3 innings.

Now, Javier will join Lance McCullers Jr., Luis Garcia, José Urquidy and Framber Valdez on the IL. The team is optimistic Valdez can return to the rotation during this eight-game road trip, but has not detailed any pitching plans beyond Brown’s start on Sunday.

Neither McCullers nor Garcia is expected back until near the All-Star break. Urquidy, who strained his forearm in spring training, still has not progressed to throwing off a mound.

Espada told reporters the team will recall top pitching prospect Spencer Arrighetti to take Javier’s spot on the active roster. Earlier this month, Arrighetti made two starts during his first stint in the major leagues. He allowed nine earned runs in seven innings.

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(Photo: Tim Warner / Getty Images)