Played baseball at Mattoon (Ill.) HS and was selected to the All-Apollo Conference First Team. He helped Mattoon win the 2019 Conference Championship...Hayden’s father, Stacey, coached him through several levels of baseball, including summer baseball with Mattoon Post 88...Majored in Exercise Science at EIU...Growing up in Mattoon, Ill. (three hours south of Chicago), Hayden grew up a Cubs fan. His first career start in the Majors came against the Cubs at Oracle Park on June 26, 2024...According to his parents, Hayden’s first word was ball. He slept with a baseball when he was young...When he was a kid, his mother, Paula, mowed a diamond into the grass during the summer to play baseball (with a tennis ball), drawing a constant stream of neighborhood kids. If the ball hit a neighbor’s house it was a homer.
2025
Made his first career Opening Day roster...began the season in the bullpen after having been a starter most of his pro career...Made his first big league relief appearance on April 2 at Houston, entering the game in the sixth inning, with SF leading the Astros, 5-3...Went 1-0 with a 2.31 ERA (6 ER, 23.1 IP) in 11 relief outings...Joined the rotation with his first start on May 20 vs. Kansas City, taking the slot of Jordan Hicks, who was moved to the bullpen...earned the win with one unearned run allowed over five innings...In his start on July 21 at Atlanta, he did not record an out, allowing five runs on a base hit, a hit batter and four walks before being removed from the game...Did not record an out on July 21 at Atlanta, giving up five runs on one hit and four walks...he became the first SF starter to not record an out since Scott Alexander on August 8, 2023, and the first Giants starter (not including openers) since Gil Heredia on June 4, 1992...He was optioned postgame on July 21 and did not return to the Majors the remainder of the season...Was 3-4 with a 6.17 ERA (29 ER, 42.1 IP) as a starter with the Giants in 2025...Went 1-3 with a 6.23 ERA (27 ER, 39 IP), 47 strikeouts and a 1.85 WHIP in 10 games (all starts) for Triple-A Sacramento.
2024
Made his MLB debut with the Giants, making 16 starts for SF...He went 5-6 with a 4.75 ERA (38 ER, 72.0 IP), with the Giants going 6-10 in his outings. Had his contract selected from Triple-A Sacramento on June 26 and made his MLB debut that night vs. Chicago...Tossed 4.2 innings and allowed three runs on six hits with five strikeouts in the outing...At 22 years and 306 days old, Birdsong became one of seven Giants starting pitchers to make their MLB debut prior to turning 23 years old since 2000, joining RHP Jerome Williams (2003), RHP Matt Cain (2005), RHP Tim Lincecum (2007), LHP Madison Bumgarner (2009), RHP Logan Webb (2019) and LHP Kyle Harrison (2023)...Began the year at Double-A Richmond and was 4-2 with a 2.05 ERA (11 ER, 48.1 IP) with 61 strikeouts in 11 starts before being promoted to Triple-A Sacramento on June 11...Made two starts for Sacramento after the promotion and posted a 5.00 ERA (5 ER, 9.0 IP) with 14 strikeouts before his eventual MLB debut on June 26...Recorded 12 strikeouts in his start against Colorado at Coors Field on July 21, the most he’d ever accumulated in an outing in his professional career...His 12 punchouts were the most by a Giants pitcher ever at Coors Field...they were also the most by a Giants rookie since Tim Lincecum fanned 12 on July 1, 2007...Birdsong threw 259 curveballs at the MLB level and batters were just 8-for-55 (.145) with 27 strikeouts off the pitch...His .145 opponent average against the curveball was sixth-best in the NL and 11th-best in the Majors and his 45% strikeout rate was sixth-best in the Majors (min. 250 pitches).
2023
Split the season between three levels and combined to go 2-5 with a 3.31 ERA (37er, 100.2ip) with 149 strikeouts overall. His 3.31 season ERA was best among SF Minor Leaguers (min 100.0ip) Started the season with Low-A San Jose and posted a 2.16 ERA over 12 games (10 starts)…struck out 70 batters in 41.2 innings of work (15.12 SO/9.0)…he held CAL league hitters to a .218 average. Had his best performance on the Fourth of July as he threw five no-hit innings and struck out a career-high 11 batters en route to a combined no-hitter for the Emeralds. Was the fourth player from the 2022 Giants draft class to reached the upper minors, joining second-rounder Carson Whisenhunt, eighth-rounder Wade Meckler and 10th-rounder John Michael Bertrand.
