Kai-Wei Teng wants to join Astros’ rotation, but a familiar flaw could be in his way

The Houston Astros have a seemingly endless supply of enigmatic arms competing for rotation spots. Rather than contenders dropping out of the mix as spring training rages on, each passing day seems to bring a new candidate into the mix.

The latest entry, Kai-Wei Teng, comes on the heels of our learning from Joe Espada that the club is now uncertain whether or not it will open the season with a six-man rotation.

Teng is an interesting character. Houston clearly liked him enough to trade away an interesting catching prospect in 21-year-old Jancel Villarroel to acquire him from the San Francisco Giants back in January.

To date, the 27-year-old right-hander has not fully broken through at the major league level. He's appeared in just 12 games (seven starts) and thrown just 40 2/3 innings in parts of 2024 and 2025, with walks being a consistent bugaboo coming in at a 12.9% rate for his career.

Kai-Wei Teng has his eyes on a spot in the Astros starting rotation

Teng has pitched exclusively out of the bullpen this spring, throwing five 2/3 innings over three appearances. He has a 3.18 ERA, though he's walked as many batters (4 ) as he's struck out so far.

A starter throughout his minor league career, he'll get the ball as a starter during the March 13 matchup against the St. Louis Cardinals. If he has his preference, he'll be a starter with the big league club the rest of the way.

“So for now, I personally like being a starter, but you know, whatever the team needs me to do, I'll do my best,” Teng said. “My main goal is to help the team win.”

That seems increasingly difficult to envision, at least to start, especially if he can't clean up the walk issues. Hunter Brown, Tatsuya Imai, Cristian Javier, and Mike Burrows are all guaranteed spots in the rotation. If the Astros go with just five, Lance McCullers Jr. and his $17 million salary seem to be the favorite for the final spot.

That doesn't mean that things can't change as the season unfolds. The Astros will no doubt shuffle the deck in the event of underperformance. Once the April gauntlet that consists of 26 games in 28 days is complete, Houston might revisit the idea of a six-man rotation if it indeed opens with just the conventional five starters to begin the year. All of these potential developments could create opportunities for Teng and a number of other guys, meaning this competition won't die down any time soon.

What is clear is that the Astros like Teng and have a plan for him. Like most of their acquisitions, they've begun tweaking with his repertoire and pitch utilization with an eye on maximizing his stuff. This isn't the first time we've heard about Teng potentially scoring a spot on the Opening Day roster, either. Earlier this month, Astros beat reporter Chandler Rome name-dropped him as a bullpen candidate to watch, both showing the faith the organization has in him and muddying the waters as to what his ultimate role will be.

The ironic thing is that if Houston does end up running a six-man rotation, Teng's best fit might be coming out of the pen as a multi-inning bulk reliever to help preserve a bullpen that would be short an arm. Either way, it's a complicated position to be in for a pitcher whom the club favors but doesn't have an obvious role. From here on out, the best he can do is try to force their hand by addressing his greatest weakness: the walks.