Kyle Harrison Bio
Kyle Christopher Harrison (born August 12, 2001) is an American professional baseball pitcher for the Milwaukee Brewers of Major League Baseball (MLB). He has previously played in MLB for the San Francisco Giants and Boston Red Sox. The Giants selected Harrison in the third round of the 2020 MLB draft, and he made his MLB debut with them in 2023 before being traded to the Red Sox in 2025 and then to the Brewers in February 2026.
Early Life and Background
Kyle Christopher Harrison was born on August 12, 2001, in San Jose, California. He grew up in Orange County, California, and then from 2009 on in Danville, California. His father is Chris Harrison, and his mother Kim played college field hockey for San Jose State University. His maternal grandfather is former left-handed major league pitcher Skip Guinn, who pitched in 68 games in parts of three seasons for the Atlanta Braves and Houston Astros from 1968 to 1971.
In 2015, Harrison was a member of the Tri-Valley All-Stars, which won the Babe Ruth 13-year-old World Series. Four years later, Harrison had the top earned run average in the 2019 WBSC U-18 Baseball World Cup while pitching for gold-medal winning Team USA, as he did not allow a run in 10 innings while striking out 12 batters.
Path to Baseball
Harrison attended De La Salle High School in Concord, California in the San Francisco Bay Area. As a sophomore in 2018, he went 9-1 with a 1.17 ERA, recording 71 strikeouts in 54 innings. He was named East Bay Athletic League Pitcher of the Year, a 2018 MaxPreps National All-American, and Cal-Hi Sports All-State Underclass. As a junior in 2019, he was 10-0 with a 1.26 ERA for the Spartans, with 103 strikeouts in 61 innings, and also played first base. As a senior in 2020, he was 2-0 with an 0.78 ERA and pitched nine innings with 18 strikeouts before the season was ended due to COVID-19.
In his high school career, Harrison was 21-1 with a 1.19 ERA in three years, striking out 192 batters in 124 innings, and held batters to a .137 batting average. By his senior year, his fastball touched 94 mph, and he also threw a high-70s slider, a change-up, and a curveball. He ultimately chose professional baseball over playing college baseball at UCLA, where he had committed to play.
Kyle Harrison Career
San Francisco Giants (2020-2025)
The San Francisco Giants selected Harrison in the third round of the 2020 MLB draft. He signed for a signing bonus of $2.5 million rather than play college baseball at UCLA. The Giants more than tripled their offer from the $710,000 slot value to sign Harrison. He did not play in a game in 2020 due to the cancellation of the minor league season because of the COVID-19 pandemic.
Harrison made his professional debut in 2021 with the Low-A San Jose Giants of the California League. Over 23 starts, he led the league with a 3.19 ERA and went 4-3 with 157 strikeouts and 14.3 strikeouts per nine innings over 98 2/3 innings. He was named the 2021 Low-A West Pitcher of the Year, the CAL Pitcher of the Year, a CAL Post-Season All-Star, and an MiLB.com Organization All-Star.
MLB Breakthrough (2023-2024)
Before the 2023 season, Harrison was ranked as the number 18 prospect in the minor leagues by MLB.com. He started the 2023 season pitching for the Triple-A Sacramento River Cats, where at 21 years of age he was the Giants number 1 prospect and the number 1 left-handed pitching prospect in the minor leagues per MLB.com.
Harrison made his major league debut on August 22, 2023 against the Philadelphia Phillies. At 22 years and 10 days old, he was the youngest Giants pitcher since Madison Bumgarner in 2009. In his debut, he pitched 3 1/3 innings, giving up five hits, two runs, hitting a batter, and recording five strikeouts. His fastball reached 97.6 mph. On August 28, in his second start against the Cincinnati Reds, Harrison pitched 6 1/3 shutout innings and struck out 11 batters, becoming the youngest Giant with that many strikeouts since Bumgarner in 2011. He finished the 2023 season with a 1-1 record and 4.19 ERA in 7 starts.
In 2024, Harrison made 24 starts for San Francisco, recording a 7-7 win-loss record and 4.56 ERA with 118 strikeouts across 124 1/3 innings pitched. He was optioned to Triple-A Sacramento to begin the 2025 season before being recalled to serve as a reliever. In eight appearances for the team, he posted a 1-1 record and 4.56 ERA with 25 strikeouts across 23 2/3 innings pitched.
Boston Red Sox and Milwaukee Brewers (2025-2026)
On June 15, 2025, the Giants traded Harrison to the Boston Red Sox along with Jordan Hicks, James Tibbs III, and Jose Bello, in exchange for Rafael Devers. Harrison made three appearances including two starts for Boston, recording a 3.00 ERA with 13 strikeouts across 12 innings pitched. On February 9, 2026, the Red Sox traded Harrison to the Milwaukee Brewers in exchange for Caleb Durbin and other players. He made his Brewers debut on March 30 against the Tampa Bay Rays.
Driving Style and Strengths
Harrison pitches with a low three-quarter release and features a mid-90s rising four-seam fastball that has reached 98 mph at times. His primary swing-and-miss pitch is a low-80s slider with big lateral break. He also throws a developing mid-80s one-seam changeup. His deceptive low below-three-quarter-slot delivery has been a hallmark of his pitching style since high school.
Notable Events and Milestones
Harrison’s minor league career through 2022 showed remarkable dominance, as he went 8-6 with a 2.93 ERA in 48 starts, striking out 343 batters in 211 2/3 innings for a 14.6 strikeouts per nine innings rate. In 2022 alone, his 186 aggregate strikeouts were the second-most of any pitcher in the minor leagues, and he led the minor leagues in both strikeouts per nine innings and whiff percentage.
Kyle Harrison Career Wins
Through June 20, 2026, Harrison has compiled a 17-10 win-loss record with a 3.88 earned run average and 278 strikeouts across his major league career spanning portions of four seasons with three franchises.
Major League Highlights
Harrison’s most notable major league performance came in his second career start on August 28, 2023, when he pitched 6 1/3 shutout innings against the Cincinnati Reds and struck out 11 batters. He was the second pitcher in Giants history to have double-digit strikeouts in his second career start, following Jeff Tesreau with the New York Giants in 1912. His standout 2024 season included 24 starts with a 7-7 record and 118 strikeouts.
Minor League Achievements
In his minor league career, Harrison earned numerous accolades including 2021 Low-A West Pitcher of the Year, 2021 CAL Pitcher of the Year, 2021 and 2022 MiLB.com Organization All-Star, and 2022 Baseball America Giants’ Minor League Player of the Year. His 2022 campaign was particularly dominant, leading the minor leagues in strikeouts per nine innings with a 14.8 rate, the highest for a pitcher in the minors since 1960.
Kyle Harrison Family
Family Background and Baseball Lineage
Harrison comes from a baseball family with professional connections. His maternal grandfather is former major league pitcher Skip Guinn, who appeared in 68 games for the Atlanta Braves and Houston Astros from 1968 to 1971. His mother Kim played college field hockey for San Jose State University. His father Chris Harrison supports his baseball career. Harrison has a younger brother Connor Harrison, nicknamed Bear.
Personal Life
Harrison maintains a presence on Instagram under the handle kyleharrison. He has shown dedication to his craft throughout his development, choosing to sign with the Giants for $2.5 million rather than attend UCLA after being selected in the third round of the 2020 MLB draft.
2025 Season Performance
The 2025 season marked a transitional year for Harrison as he split time between three organizations. He began the year with the Giants’ Triple-A Sacramento affiliate before being recalled to the major league club in early May, this time in a relief role rather than as a starter. His eight appearances with San Francisco resulted in a 1-1 record with a 4.56 ERA and 25 strikeouts in 23 2/3 innings. Following the mid-June trade to Boston, Harrison made three appearances including two starts for the Red Sox, recording a 3.00 ERA with 13 strikeouts in 12 innings. The trade to the Red Sox as part of a major package for Rafael Devers represented a significant opportunity for Harrison to contribute to a contender. He finished the season with a combined record reflecting his adjusted role and the transition to a new organization mid-season.