Zack Kelly Bio
Zachery Reed Kelly (born March 3, 1995) is an American professional baseball pitcher for the Boston Red Sox of Major League Baseball (MLB). He made his MLB debut in 2022 after beginning his professional career as an undrafted free agent signed by the Oakland Athletics in 2017. Kelly also pitched in the Los Angeles Angels organization before establishing himself in Boston as a reliable relief pitcher.
Early Life and Background
Kelly grew up in the Botetourt County area of Virginia and graduated from Lord Botetourt High School in Daleville, Virginia. After high school, he enrolled at Concord University, where he played college baseball in NCAA Division II for the Concord Mountain Lions in 2014, working primarily as a starting pitcher.
After his sophomore year, Kelly transferred to Newberry College in South Carolina to play for the Newberry Wolves, another Division II program. As a senior in 2017, he produced a 3.72 earned run average (ERA) and recorded 94 strikeouts across 82 and one-third innings pitched, a workload that drew attention from professional scouts despite going unselected in the 2017 MLB draft.
Path to Professional Baseball
Unselected in the 2017 MLB draft, Kelly signed with the Oakland Athletics as an undrafted free agent for a $500 signing bonus. He pitched in the rookie-level Arizona League during 2017, but the Athletics released him in April 2018. Kelly later reflected that he probably lost money during his first professional season.
Kelly signed with the Los Angeles Angels organization and moved through three teams in the Angels’ system, reaching the Class A-Advanced level with the Inland Empire 66ers of the California League. He appeared in 18 total relief appearances and posted a 2.93 ERA while striking out 41 batters in 43 innings. After the Angels released Kelly during the COVID-19 shutdown in 2020, he underwent surgery on his elbow to have a ligament reattached, a setback he worked through before catching on with Boston.
Zack Kelly Career
Early Career (2017–2020)
Kelly’s professional career began modestly in the Oakland Athletics’ rookie-level Arizona League affiliate in 2017. After being released by Oakland in April 2018, he signed with the Los Angeles Angels and climbed through their minor league system, reaching High-A Inland Empire and Double-A Mobile before the Angels parted ways with him during the 2020 shutdown.
The 2020 elbow surgery was a turning point in Kelly’s career. After his release, he underwent a procedure to reattach a ligament in his elbow and used the recovery period to rebuild his arm strength and command. His resilience through that setback helped set the stage for his eventual breakthrough with Boston.
Boston Red Sox Breakthrough (2021–2023)
On January 4, 2021, Kelly signed a minor league contract with the Boston Red Sox organization. He split that season between the Double-A Portland Sea Dogs and the Triple-A Worcester Red Sox, posting a 1.69 ERA in 21 relief appearances for Portland and a 2.89 ERA in 15 relief appearances for Worcester. In 2022, the Red Sox invited Kelly to spring training as a non-roster player before returning him to Worcester, where he worked to a 2.72 ERA before his promotion.
Kelly was added to Boston’s major-league roster on August 29, 2022, and made his MLB debut that evening against the Minnesota Twins. In 13 relief appearances with Boston that year, he went 1–0 with a 3.95 ERA and 11 strikeouts in 13 and two-thirds innings. He was also the 2022 recipient of the Lou Gorman Award issued by the Red Sox organization in recognition of his perseverance and development.
In 2023, Kelly began the year in Boston’s bullpen before right elbow inflammation sent him to the injured list on April 13. He was transferred to the 60-day injured list three days later and underwent a successful ulnar nerve transposition revision on May 3, an operation that kept him out roughly four months. Kelly was activated on September 24 and successfully pitched for the Red Sox after going 166 days between major league appearances.
Boston Red Sox Continued Role (2024–2025)
Kelly was optioned to Triple-A Worcester to begin the 2024 season, but he was recalled on April 24 to replace injured pitcher Brayan Bello. After another short stint in Worcester to make room for newly signed pitcher Brad Keller, Kelly returned to the majors on June 5 and made his first MLB start on June 9 against the Chicago White Sox, pitching two scoreless innings as an opener.
Across 49 regular-season appearances in 2024, Kelly went 6–3 with a 3.97 ERA and 61 strikeouts in 56 and two-thirds innings, serving as a steady middle reliever. In 2025, he made 28 bullpen appearances for the Red Sox, accumulating a 1–3 record and 4.58 ERA with 35 strikeouts across 35 and one-third innings pitched.
Driving Style and Strengths
Kelly has carved out his role as a dependable middle reliever who can handle multiple innings and adapt between long relief and short stints. His experience coming back from two significant elbow surgeries has shaped a calm, resilient approach on the mound, and he has shown the command and pitch efficiency needed to navigate high-leverage spots for Boston’s bullpen.
Notable Events and Milestones
Kelly’s signature milestones include his MLB debut against the Minnesota Twins on August 29, 2022, his first MLB start against the Chicago White Sox on June 9, 2024, and his selection as the 2022 Lou Gorman Award winner. His return from a 166-day absence in September 2023 also stands out as one of the more dramatic comeback stories in recent Red Sox bullpen history.
Zack Kelly Career Highlights
Kelly’s verified career highlights center on his climb from undrafted free agent to established MLB reliever. Through May 19, 2026, his major league numbers with the Red Sox include an 8–8 win–loss record, a 4.04 ERA, and 127 strikeouts, figures that reflect a long developmental arc through Oakland, Los Angeles, and Boston.
Major League Highlights
Kelly’s first major league win came during his 2022 debut season with Boston, a year capped by the Lou Gorman Award. He has since posted a 6–3 record in 2024 and a 1–3 mark in 2025, while making his first MLB start against the Chicago White Sox on June 9, 2024, in a two-inning opening assignment.
Minor League and Other Performances
In the Angels’ system, Kelly reached High-A Inland Empire with a 2.93 ERA in 18 relief appearances and later worked at Double-A Mobile with a 3–7 record and 4.88 ERA across 21 games. With Boston’s affiliates, he earned a 1.69 ERA at Double-A Portland and a 2.89 ERA at Triple-A Worcester in 2021 before adding a 2.72 ERA at Worcester in 2022.
Zack Kelly Family
Family Background and Racing Lineage
Public information about Kelly’s parents and broader family background is limited. What is clear is that he grew up in the Botetourt County area of Virginia and attended Lord Botetourt High School in Daleville before beginning his college baseball journey at Concord University.
Personal Life
Kelly is married to his wife, Brittany, and the couple resides in South Carolina during the offseason. He and Brittany welcomed their first child, a son, in September 2022, an arrival that coincided with Kelly’s first major league season and required a short stay on the paternity list.
2025 Season Performance
Kelly spent the 2025 season working out of the Boston bullpen, making 28 appearances and finishing with a 1–3 record and a 4.58 ERA. He struck out 35 batters across 35 and one-third innings, continuing in the middle-relief role he had built since his 2022 debut. The campaign offered fewer high-leverage moments than his 2024 breakout, but Kelly remained a dependable option for Boston’s relief corps.
His 2025 workload reflected the typical up-and-down rhythm of a non-closing reliever, with stretches of strong work interrupted by the offensive environment of the American League. The Red Sox continued to rely on his ability to record outs in middle innings and to step into multi-inning assignments when starters exited early.
Looking ahead, Kelly’s standing with Boston entering the next season hinges on his ability to keep his ERA in check and to stay healthy after two prior elbow surgeries. His established rapport with the Red Sox pitching staff and his history of bouncing back from adversity position him as a veteran depth piece in the bullpen for the year to come.
