Struggling right-hander Adrian Houser is being moved from the Giants rotation to the bullpen, manager Tony Vitello told the California Post’s Evan Webeck (multiple links) and other reporters. With Tyler Mahle nearing a return from the 15-day injured list, Houser looks to the odd man out of the rotation, as the Giants will instead keep Trevor McDonald in a starting role.
Houser is no stranger to relief pitching, as he worked as a swingman with the Brewers earlier in his career and was moved to the Mets’ bullpen after some other struggles as a starter early in the 2024 season. That said, it’s obviously not a great outcome for either Houser or the Giants just six months after the right-hander inked a two-year, $22MM free agent deal.
Houser expressed his disappointment over the role change, telling Webeck that “I’m not going to be happy about it, but I understand. I signed here to be a starter. I didn’t sign here to be in the bullpen. So I’m gonna do everything I can to get back in the rotation.”
Over his 10 Major League seasons, Houser has generally delivered okay numbers as a back-end starter, with a career 4.20 ERA and 50.3% grounder rate over 799 2/3 innings in the Show. Houser’s ability to keep the ball on the ground has mitigated his lack of strikeouts, though this year, his grounder rate has dropped to 40.5%. The increase in fly balls has been just one of many issues on a troublingly blue Statcast card for Houser, and his 5.73 ERA over 66 innings underlines his lack of results.
Mahle also posted a 6.04 ERA over 56 2/3 innings before a hamstring strain sent him to the IL on May 27. Between Mahle and Houser, the Giants haven’t received much return on the $32MM spent on their rotation in free agency this past winter. The lack of production from the rotation has only been part of the problem in an overall rough season for a Giants team that entered today’s action with a 31-44 record.
With the front office already considering selling at the deadline, Mahle is an obvious trade chip as a rental player, assuming that he can regain any of his old form before August 3. That means Mahle will probably get plenty of opportunity to get on track before the deadline, closing one possible door for Houser’s rotation return. As for McDonald, the rookie has a 4.64 ERA over eight starts and 42 2/3 innings pitched, and the Giants would surely want to see what McDonald can do as the team is beginning to look ahead to 2027.
If Mahle or Robbie Ray are dealt at the deadline, Houser could be moved back into one of the open slots in San Francisco’s rotation. Houser’s own trade value is next to nil at this point given both his lack of success this year, and his remaining salary — about $3MM left this year, $9.5MM in 2027, and a $4MM buyout of a $12.5MM club option for 2028.









