Geoff Hartlieb Bio
Geoffrey Thomas Hartlieb, born on December 9, 1993, is an American professional baseball pitcher currently in the Athletics organization. A right-handed reliever, Hartlieb has spent the bulk of his career moving between Triple-A rosters and short stints in the Major Leagues, suiting up for seven organizations since his professional debut. He is best known for his work in the Pittsburgh Pirates bullpen during the 2019 and 2020 seasons, when he earned his first sustained taste of big-league action. Standing as a durable journeyman, he has continued to bounce back from waivers and free agency, most recently signing a minor league deal with the Oakland Athletics on November 20, 2025.
Early Life and Background
Geoffrey Thomas Hartlieb was born on December 9, 1993, in Highland, Illinois, a small city on the Mississippi River across from Saint Louis. He grew up locally and attended Highland High School, where he distinguished himself in multiple sports during his teenage years. As a junior and senior, Hartlieb earned all-state recognition in basketball, showcasing the kind of athleticism that would later help him on the mound.
Interestingly, Hartlieb was so focused on basketball that he actually quit baseball at the end of high school rather than pursue it competitively. He enrolled at Quincy University in Quincy, Illinois, in 2013 and spent his freshman year playing college basketball for the Hawks. After a year away from the diamond, his love of the game drew him back, and he transferred to Lindenwood University in Saint Charles, Missouri, where he played college baseball from 2014 through 2016.
Path to Baseball
While at Lindenwood, Hartlieb drew the attention of professional scouts. The New York Mets selected him in the 37th round of the 2015 MLB Draft, but he did not sign and returned to Lindenwood for his senior season. That decision paid off the following year, when the Pittsburgh Pirates took him in the 29th round of the 2016 MLB Draft. He signed with the organization and began his climb through the minor leagues.
Hartlieb’s development followed a steady ladder through Pittsburgh’s farm system. He opened his professional career with the Bristol Pirates in 2016, posting a 4–1 record with a 4.44 ERA in 26 innings. In 2017, he split time between the West Virginia Power and the Bradenton Marauders, going 2–6 with a 2.12 ERA across 63⅔ innings. By 2018, he had advanced to the Altoona Curve, where he went 8–2 with a 3.24 ERA in 58 innings, and he closed the year with a stint in the Arizona Fall League for the Surprise Saguaros.
Geoff Hartlieb Career
Early Career (2016–2018)
Hartlieb’s first three professional seasons were spent in the lower and middle levels of the Pittsburgh Pirates system, where he established himself as a reliable relief arm. After a respectable debut with Bristol, he showed improved control and strikeout ability in the South Atlantic and Florida State Leagues. His 2.12 ERA across two levels in 2017 helped him earn a promotion to Altoona, where he became a key piece of the Curve bullpen.
The 2018 season represented a turning point. Going 8–2 with a 3.24 ERA in 58 innings for the Altoona Curve, Hartlieb put himself firmly on Pittsburgh’s major-league radar. The Arizona Fall League invitation that followed gave him valuable experience against some of the game’s top prospects and set the stage for his Triple-A promotion the next spring.
Pittsburgh Pirates Breakthrough (2019–2021)
Hartlieb opened the 2019 season with the Triple-A Indianapolis Indians before receiving his first big-league call-up. The Pittsburgh Pirates promoted him to the majors on May 17, 2019, and he made his major-league debut on May 18 against the San Diego Padres. He went on to appear in 22⅓ innings for Pittsburgh in 2020, pitching to a 3.63 ERA while allowing only one home run, a strong performance in a shortened pandemic season.
His 2021 campaign was more difficult. After splitting the year between Indianapolis and Pittsburgh, Hartlieb struggled to a 7.71 ERA in four major-league appearances and was designated for assignment on July 3, 2021. The brief Pirates tenure, however, gave him the foundation he needed to navigate the rest of his career as a bullpen depth piece.
New York Mets and Boston Red Sox (2021–2022)
Hartlieb was claimed off waivers by the New York Mets on July 9, 2021, and was assigned to the Triple-A Syracuse Mets. He appeared in seven games for New York that season, but struggled to an 11.00 ERA with nine strikeouts and was designated for assignment on September 2, 2021. The Boston Red Sox claimed him off waivers on September 4, 2021, and optioned him to the Triple-A Worcester Red Sox before designating him for assignment again on September 23.
Hartlieb spent the entire 2022 season with Triple-A Worcester, registering a 3–6 record and a 5.16 ERA with 64 strikeouts across 61 innings. He elected free agency on November 10, 2022.
Miami Marlins (2023)
On November 29, 2022, Hartlieb signed a minor league deal with the Miami Marlins. In 26 games for the Triple-A Jacksonville Jumbo Shrimp, he posted a 3.18 ERA with 36 strikeouts and six saves in 34 innings. The Marlins selected his contract on August 6, 2023, and he made his Miami debut that same day, tossing an inning against the Texas Rangers and allowing one run while striking out two. He made just one more appearance before being designated for assignment on September 6, eventually electing free agency on October 5, 2023.
Colorado Rockies (2024)
Hartlieb signed a minor league contract with the Colorado Rockies on November 13, 2023. In 22 games for the Triple-A Albuquerque Isotopes, he logged a 5.61 ERA with 34 strikeouts across 33⅔ innings. The Rockies selected his contract on June 8, 2024, and he appeared in five games for Colorado, struggling to a 9.00 ERA with seven strikeouts across nine innings. He was designated for assignment on June 22 and elected free agency on October 2, 2024.
New York Yankees (2025)
On October 18, 2024, Hartlieb signed a minor league contract with the New York Yankees. He posted a 3–2 record and 3.34 ERA with 38 strikeouts and two saves across 35 innings in 24 appearances for the Triple-A Scranton/Wilkes-Barre RailRiders. The Yankees selected his contract on June 30, 2025, and he made his only appearance on July 1, allowing three runs in one inning against the Toronto Blue Jays. After a brief re-signing on July 6, he was designated for assignment a second time on July 9 and elected free agency on July 11.
Detroit Tigers and Kansas City Royals (2025)
On July 12, 2025, Hartlieb signed a minor league contract with the Detroit Tigers. He made two scoreless appearances for the Triple-A Toledo Mud Hens, recording one win, four strikeouts, and one save across 4⅓ innings. The Tigers selected his contract on July 24, but he was designated for assignment on July 26 after two games. He was released on August 19 after a brief re-signing.
Hartlieb signed a minor league contract with the Kansas City Royals on August 27, 2025. He made seven appearances for the Triple-A Omaha Storm Chasers, going 0–1 with a 9.00 ERA and 10 strikeouts over eight innings. He elected free agency on November 6, 2025.
Notable Events and Milestones
Hartlieb’s most memorable career moment remains his major-league debut on May 18, 2019, against the San Diego Padres, after years of grinding through the Pittsburgh farm system. His 2020 season with the Pirates, in which he posted a 3.63 ERA and surrendered just one home run in 22⅓ innings during the shortened campaign, stands as his most consistent major-league stretch. The 2023 season also marked a personal best in Triple-A saves, when he recorded six for the Jacksonville Jumbo Shrimp.
2025 Season Performance
Hartlieb’s 2025 season was defined by constant movement between organizations. He began the year in the New York Yankees system, putting together a strong 3.34 ERA across 24 appearances for the Scranton/Wilkes-Barre RailRiders. His first major-league appearance of the year came on July 1 against the Toronto Blue Jays, in which he struggled with command before being designated for assignment.
After brief stops in Detroit and Kansas City, Hartlieb closed 2025 with a short Triple-A stint in Omaha. His ability to land on his feet through free agency and waivers again underscored his value as a depth reliever. On November 20, 2025, he signed a minor league contract with the Oakland Athletics, positioning him for a fresh opportunity in the 2026 season.