WEST SACRAMENTO -- A season after they suffered a series of key injuries in their starting rotation, the Astros were dealt their first major health setback of 2026 when ace right-hander Hunter Brown was placed on the 15-day injured list Sunday with a shoulder strain before their 12-10 walk-off loss to the A's.
Brown, who had never been on the IL previously in his career, flew to Houston to be examined by team doctors. Astros manager Joe Espada said Brown felt an issue with his shoulder during his routine throwing program on Friday. No timetable for his return will be known until he’s diagnosed further.
“It didn’t feel right and then he stopped throwing,” Espada said. “We proceeded to get him to see the doctors. He got imaging done here, and once we got those, we sent him home.”
Espada said Cody Bolton will start Monday’s series opener against the Rockies in Denver, which was Brown’s next scheduled start. Bolton, who threw three innings in relief on Tuesday, will be making his first Major League start.
Brown made his first Opening Day start March 26 against the Angels and threw 102 pitches in 4 2/3 scoreless innings. He threw six innings of one-run ball in his second start on Tuesday against the Red Sox, but was pulled after only 78 pitches. Espada said he wanted to dial back Brown’s pitch count after his heavy Opening Day workload.
“He’s never been injured and this is new for all of us,” Espada said. “He didn’t sound concerned, which is good, but it’s new. We’re going to let the doctors evaluate him and we’ll see where we go from there.”
The Astros will likely call up right-hander Spencer Arrighetti soon from Triple-A considering they’re planning to go to a six-man rotation following Thursday’s day off before a four-game series in Seattle. Arrighetti threw 78 pitches in 4 1/3 scoreless innings in his start Friday for the Space Cowboys in Jacksonville, Fla.
Ryan Weiss, who was signed in the offseason as a starter, threw 38 pitches in three scoreless relief innings in Friday’s series opener against the A’s and could be a candidate to jump into the rotation.
If Brown is lost for an extended period of time, it would be a massive blow for the Astros. He is coming off the best season of his four-year career, which earned him a third-place finish in American League Cy Young Award voting. He assumed the role of Houston’s ace, going 12-9 with a 2.43 ERA and a career-low WHIP of 1.03 in 31 starts in 2025. He struck out a career-high 206 batters in 185 1/3 innings and allowed only 133 hits and was a constant in a rotation rocked by injuries in ‘25.
Last year, the Astros lost three-fifths of their rotation to begin the season to significant injuries. Hayden Wesneski and Ronel Blanco wound up having Tommy John surgery early in the season. Arrighetti missed four months with a fractured right thumb and returned on Aug. 6, going 0-4 with a 5.26 ERA in five starts before being shut down with right elbow inflammation.
A third starting pitcher -- left-hander Brandon Walter -- wound up having Tommy John surgery in September. The Astros did get Cristian Javier and Luis Garcia back from Tommy John surgeries last year, and Lance McCullers Jr. made his return following 2 1/2 seasons on the injured list. Garcia underwent a second Tommy John surgery in October and was later released.
Because they suffered so many injuries last year and lost lefty Framber Valdez in free agency, the Astros focused on beefing up their starting pitching depth in the offseason, which led to the acquisitions of Tatsuya Imai, Mike Burrows, Kai-Wei Teng and Weiss, among others.
Brown had the longest scoreless innings streak in the Major Leagues last year at 28 innings from April 3-28 -- the fifth-longest single-season streak by an Astros starter in history. He was named the AL Pitcher of the Month for June after posting a 1.19 ERA and a 0.82 WHIP in 30 1/3 innings, with the Astros winning all five of his starts during the month. He began the season with seven consecutive quality starts.