Geoff Hartlieb Bio
Geoffrey Thomas Hartlieb is an American professional baseball pitcher in the Athletics organization. He has previously played in Major League Baseball (MLB) for the Pittsburgh Pirates, New York Mets, Miami Marlins, Colorado Rockies, New York Yankees, and Detroit Tigers.
Born on December 9, 1993, in Highland, Illinois, Hartlieb has built a journeyman career across multiple organizations since debuting in 2019. Known for his bullpen work and Triple-A consistency, he has become a familiar presence on minor league deals and short major league stints.
Early Life and Background
Geoffrey Thomas Hartlieb grew up in Highland, Illinois, where he attended Highland High School. A multi-sport athlete, he was an all-state basketball player during his junior and senior years and originally quit baseball at the end of high school to focus on hoops.
His first year of college came at Quincy University in Quincy, Illinois, in 2013, where he played college basketball for the Hawks. After one season, he transferred to Lindenwood University in Saint Charles, Missouri, to resume his baseball career from 2014 through 2016.
While at Lindenwood, Hartlieb drew early professional interest when the New York Mets selected him in the 37th round of the 2015 MLB draft. He chose not to sign and returned to school, setting the stage for his eventual professional breakthrough a year later.
Path to Baseball
Hartlieb’s pivot back to baseball at Lindenwood University proved pivotal. His performance with the Lions caught the attention of scouts, and he re-entered the 2016 draft with stronger momentum and a clearer pitching identity.
The Pittsburgh Pirates selected Hartlieb in the 29th round of the 2016 MLB draft, and he signed his first professional contract. His path through the minor leagues began immediately, and his rapid development suggested he could reach the majors within a few seasons.
Geoff Hartlieb Career
Early Career (2016–2018)
Hartlieb spent his first professional season in 2016 with the Bristol Pirates, posting a 4–1 record and a 4.44 earned run average (ERA) over 26 innings. He showed enough promise to advance to higher levels in subsequent seasons.
In 2017, he split time between the West Virginia Power and the Bradenton Marauders, combining for a 2–6 record with a sharp 2.12 ERA in 63 2/3 innings. The following year, pitching for the Altoona Curve, Hartlieb went 8–2 with a 3.24 ERA across 58 innings and added experience with the Surprise Saguaros of the Arizona Fall League during the 2018 offseason.
Pittsburgh Pirates Breakthrough (2019–2021)
Hartlieb opened 2019 with the Triple-A Indianapolis Indians before earning his first major league call-up. The Pirates promoted him on May 17, 2019, and he made his MLB debut on May 18 against the San Diego Padres.
During the shortened 2020 season, Hartlieb posted a 3.63 ERA for Pittsburgh, allowing just one home run across 22 1/3 innings. In 2021, however, he struggled to a 7.71 ERA in four major league appearances before being designated for assignment on July 3, 2021.
New York Mets (2021)
On July 9, 2021, the New York Mets claimed Hartlieb off waivers and assigned him to the Triple-A Syracuse Mets. He appeared in seven games for New York but posted an 11.00 ERA with nine strikeouts before being designated for assignment on September 2.
Boston Red Sox (2021–2022)
The Boston Red Sox claimed Hartlieb off waivers on September 4, 2021, and optioned him to the Triple-A Worcester Red Sox. He spent the full 2022 season with Worcester, going 3–6 with a 5.16 ERA and 64 strikeouts in 61 innings before electing free agency on November 10, 2022.
Miami Marlins (2023)
Hartlieb signed a minor league deal with the Miami Marlins on November 29, 2022, and pitched for the Triple-A Jacksonville Jumbo Shrimp, recording 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 day against the Texas Rangers. He was designated for assignment on September 6 and elected free agency after the season.
Colorado Rockies (2024)
Hartlieb signed a minor league contract with the Colorado Rockies on November 13, 2023, and pitched for the Triple-A Albuquerque Isotopes, posting a 5.61 ERA with 34 strikeouts across 33 2/3 innings. Colorado selected his contract on June 8, 2024, and he appeared in five games, struggling to a 9.00 ERA before being designated for assignment on June 22. He elected free agency on October 2.
New York Yankees (2025)
Hartlieb signed a minor league deal with the New York Yankees on October 18, 2024, and pitched for the Triple-A Scranton/Wilkes-Barre RailRiders, going 3–2 with a 3.34 ERA, 38 strikeouts, and two saves across 35 innings. The Yankees selected his contract on June 30, 2025, but he was designated for assignment the next day after allowing three runs in one inning against the Toronto Blue Jays. After a brief re-signing and a second designation for assignment, he elected free agency on July 11, 2025.
Detroit Tigers (2025)
On July 12, 2025, Hartlieb signed a minor league deal with the Detroit Tigers. He made two scoreless appearances for the Triple-A Toledo Mud Hens, earning one win, four strikeouts, and one save across 4 1/3 innings. The Tigers selected his contract on July 24, and he appeared in two games before being designated for assignment on July 26. He re-signed with the organization on a minor league deal the next day and was released on August 19.
Kansas City Royals (2025)
Hartlieb signed a minor league contract with the Kansas City Royals on August 27, 2025, and made seven appearances for the Triple-A Omaha Storm Chasers. He went 0–1 with a 9.00 ERA and 10 strikeouts across eight innings before electing free agency on November 6.
Athletics Era (2025–Present)
On November 20, 2025, Hartlieb signed a minor league contract with the Athletics, where he continues his professional career. His role within the organization’s pitching depth remains a work in progress as he looks to add to his major league resume.
Notable Events and Milestones
Hartlieb’s most notable milestone came on May 18, 2019, when he made his major league debut with the Pittsburgh Pirates against the San Diego Padres. He has since appeared in the majors for six different organizations, a testament to his durability and adaptability across the league.
Geoff Hartlieb Family
Family Background and Racing Lineage
Personal Life
2025 Season Performance
Hartlieb’s 2025 season was defined by constant movement between organizations. He opened the year in the Yankees’ minor league system before a brief major league appearance on July 1 against the Toronto Blue Jays led to his designation for assignment.
He then bounced through the Detroit Tigers and Kansas City Royals organizations, splitting time between Triple-A affiliates and short major league stints. His combined production reflected the difficulty of finding sustained major league footing amid frequent transitions.
By season’s end, Hartlieb signed with the Athletics on November 20, 2025, positioning himself for an opportunity in the 2026 campaign. His veteran bullpen experience and consistent Triple-A production make him a depth option as he enters the next chapter of his career.