The San Francisco Giants enter Spring Training 2026 facing rotation questions that could define their season. Camp in Scottsdale will reveal how stable the staff truly is, and no player carries more uncertainty than Hayden Birdsong. For the Giants, Birdsong represents both upside and risk, making him the player with the most to prove as workouts begin.
Birdsong flashed real promise early in 2025. The 24-year-old right-hander opened the season in the bullpen and posted a 2.31 ERA across 11 appearances. His fastball exploded on hitters, and he attacked the strike zone with confidence. The Giants rewarded that performance by moving him into the rotation in May, hoping he could stabilize a staff searching for internal answers.
The transition exposed deeper issues. Over 10 starts, Birdsong posted a 6.17 ERA, walked 27 hitters, and surrendered six home runs in 42 1/3 innings. His command wavered. His arm-side misses multiplied. By July 22, the Giants optioned him to the Sacramento River Cats in search of mechanical adjustments and renewed confidence. The demotion marked a pivotal point in his development.
The struggles followed him to Triple-A. In 10 starts for Sacramento, Birdsong recorded a 6.23 ERA and issued 30 walks over 39 innings. Even as the Giants faced rotation strain after trading Kyle Harrison and absorbing injuries to Landen Roupp and Carson Whisenhunt, they declined to recall Birdsong in September. Instead, Kai-Wei Teng, Carson Seymour, and Trevor McDonald received opportunities, a clear indication of where Birdsong stood within the organization.
The focus now is on refinement and execution. Birdsong’s path back into the conversation depends on cleaning up his mechanics, trusting his pitch mix, and consistently attacking the strike zone rather than trying to be overly precise. The organization still believes his velocity and overall arsenal are major league caliber, but results will hinge on whether he can throw strikes under pressure.
The competition has intensified. The Giants signed Adrian Houser to a two-year deal and added Tyler Mahle on a one-year contract, reinforcing the top of the rotation. Logan Webb remains the staff anchor, but depth behind him carries question marks. Both Houser and Mahle have dealt with durability concerns in recent seasons. This reality means the Giants will likely need secondary starters to cover around a dozen starts over the course of the 2026 season.
Birdsong’s opportunity lies within that window. If he demonstrates improved command during spring training, he can reenter the conversation as a viable depth option with upside. His fastball’s life and developing secondary pitches still give him a higher ceiling than many internal alternatives. If the walks persist, the Giants may hesitate again, and his role could shrink further.
Spring training tends to favor reliability over raw stuff. For Birdsong, velocity will matter less than his ability to consistently throw strikes and limit walks. The coaching staff will focus on efficiency and command rather than radar-gun readings. Results will determine whether he earns another opportunity. The team is not looking for an immediate Cy Young finalist in the young right-hander—they are looking for control and consistency.
The margin for error is thin. The Giants have not reached the postseason since 2021, when they won a franchise-record 107 games and captured the National League West before falling to the Los Angeles Dodgers in the National League Division Series. That benchmark still shapes the club's expectations, making prolonged rotation instability unaffordable. Birdsong’s development will influence roster construction, bullpen usage, and long-term planning. A rebound would provide a cost-controlled arm capable of absorbing meaningful innings, while continued inconsistency would force the front office to rely on lower-tier depth options.
Spring training is about evaluation, but it is also about trajectory. Birdsong’s regression in 2025 does not erase his talent. It does, however, place urgency on his 2026 performance. The Giants need clarity before Opening Day, and Birdsong needs validation that his mechanical reset has worked.
If he throws strikes and attacks hitters, he can reclaim a role in the Giants’ rotation. If not, the questions that defined last summer will follow him into another uncertain season.
