For the better part of a month, Kai-Wei Teng has been one of the few reliable arms in a Houston Astros bullpen under siege. On Tuesday in Baltimore, he gets a different assignment.
Teng will start the series opener against the Orioles, manager Joe Espada confirmed Monday, becoming the 11th different pitcher to start a game for Houston in its first 30 contests. It is a move the Astros did not make lightly: Teng has been arguably their best reliever this season, and pulling him from the bullpen only deepens a problem the organization has been managing since Opening Day.
But need at the front of games has won out.
The 11-18 Astros enter Monday with the second-highest rotation ERA in the majors, still without Hunter Brown, Cristian Javier, and Tatsuya Imai—three of their five Opening Day starters—along with fill-in Cody Bolton. Spencer Arrighetti’s seven-inning outing Sunday against the Yankees was just the second time this season an Astros starter completed seven innings.
Teng, acquired from San Francisco in an offseason trade, has been a different story. In 16⅔ relief innings across 11 appearances, he has posted a 2.16 ERA with nine hits and 16 strikeouts allowed. His sweeper has been particularly difficult to square up—hitters are 2-for-27 against it with a 32.6 percent swing-and-miss rate. His four-seam fastball velocity is up nearly two miles per hour from last season, averaging 94.9 mph compared to 93.2 in 2025, and he has leaned more heavily on his sinker as a complement.
Espada acknowledged Friday that Teng’s effectiveness made the decision complicated. The manager said Teng had been phenomenal bridging to the back end of the bullpen against both righties and lefties, making it difficult to justify a change.
“We also have to see as a team, as a whole, what we need,” Espada said.
What the team needs, it turns out, is length. Only four major-league teams had received fewer innings from their starters than Houston entering Monday. That burden has fallen squarely on a bullpen already missing closer Josh Hader, which has logged more relief innings than all but three teams in baseball and carries the highest bullpen ERA in the majors at 6.31.
The alternative to Teng on Tuesday was Ryan Weiss, who had been on turn to pitch. Weiss has not finished the fourth inning in either of his two rotation starts, and his 14 walks in 18 innings make him one of the most walk-prone pitchers on a staff that has issued the most free passes in the majors. Teng, by comparison, has walked six in his 16⅔ innings of work.
Teng made seven starts for the Giants last season, so the swingman role is not unfamiliar territory. That said, he has not thrown more than 2⅔ innings or 39 pitches in any appearance this season and will not be stretched out to a full starter’s workload Tuesday. Weiss is among the options to follow him out of the bullpen, depending on how far Teng can go.
The Astros are gambling that a pitcher finding his footing in relief can translate that success to a starting role without skipping a beat and that the bullpen can absorb the loss of its steadiest presence. It is the kind of calculation this roster has forced repeatedly in April.
Tuesday will show whether it pays off.
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