SAN FRANCISCO — Hayden Birdsong’s strong start to 2025 vanished by summer, leaving the San Francisco Giants pitcher fighting for his big-league future. As workouts kick off in Scottsdale, the young right-hander carries the heaviest burden on a rotation stacked with question marks.

Birdsong impressed out of the bullpen early last year. He logged a 2.31 ERA over 11 appearances, pounding the strike zone with a lively fastball. Giants officials him to the rotation in May, seeking internal stability amid staff woes.

The move backfired. In 10 starts, Birdsong surrendered a 6.17 ERA, walked 27 batters and allowed six home runs across 42 1/3 innings. His command deserted him. Misses to the arm side piled up. On July 22, the Giants optioned him to Triple-A Sacramento for mechanical tweaks.

Problems persisted in the minors. Birdsong posted a 6.23 ERA with 30 walks in 39 innings over 10 starts for the River Cats. Despite rotation crunches from trading Kyle Harrison and injuries to Landen Roupp and Carson Whisenhunt, the Giants kept him down in September. Call-ups went to Kai-Wei Teng, Carson Seymour and Trevor McDonald instead.

Now refinement rules his offseason. Birdsong needs cleaner mechanics, faith in his pitch mix and relentless zone attacks. Officials still rate his velocity and arsenal as major-league ready. Pressure strikes will test it all.

Competition sharpened this winter. The Giants inked Adrian Houser to a two-year pact and Tyler Mahle for one year, bolstering the top end. Logan Webb anchors the staff. Depth lags, though. Houser and Mahle battled injuries lately, opening slots for about a dozen starts in 2026.

Birdsong eyes that gap. Spring command gains could slot him as a high-upside depth piece. His fastball bite and growing secondaries outshine some rivals. Persistent walks might sideline him further.

Reliability trumps raw velocity in camp. Coaches will drill efficiency over gun readings. They seek control from Birdsong, not Cy Young bids. Results dictate his path.

Stakes run high. The Giants last made the playoffs in 2021, winning 107 games for a National League West crown before a division series loss to the Dodgers. Rotation flux can’t linger. Birdsong’s arc shapes roster calls, bullpen plans and front-office moves. A bounce-back delivers cheap innings. Stumbles push cheaper arms into play.

Scottsdale offers reset chances. Birdsong’s 2025 slide doesn’t bury his tools. It demands proof his fixes stick before Opening Day. Strikes and aggression could reclaim his rotation shot. Failure revives last year’s doubts.