|Pittsburgh Pirates – No. 72|
|Born: December 9, 1993|
|May 18, 2019, for the Pittsburgh Pirates|
|MLB statistics |
(through September 15, 2019)
|Earned run average||8.54|
Hartlieb attended Highland High School in Highland, Illinois. Hartlieb was all-state in basketball his junior and senior years of high school, and originally quit baseball at the end high school. He attended Quincy University in Quincy, Illinois his freshman year of college in 2013 and played college basketball for the Hawks. He then transferred to Lindenwood University in Saint Charles, Missouri to play college baseball from 2014 through 2016. He was drafted by the New York Mets in the 37th round of the 2015 MLB draft, but did not sign and returned to Lindenwood. He was then drafted by the Pittsburgh Pirates in the 29th round of the 2016 Major League Baseball draft and signed.
Hartlieb spent his first professional season of 2016 with the Bristol Pirates, going 4–1 with a 4.44 ERA in 26 innings. He spent the 2017 season with the West Virginia Power and the Bradenton Marauders, combining to go 2–6 with a 2.12 ERA in 63.2 innings. In 2018, he played for the Altoona Curve, going 8–2 with a 3.24 ERA in 58 innings. During the 2018 offseason, he played for the Surprise Saguaros of the Arizona Fall League.
- WGEL (May 20, 2019). "Highland Native To Majors". WGEL 101.7 FM. Retrieved May 21, 2019.
- Stephen J. Nesbitt (May 21, 2019). "'Dear Mom': How Geoff Hartlieb carried his mother's memory to the majors". The Athletic. Retrieved May 21, 2019.
- Criddle, Dean. "Highland's Hartlieb turns down Mets, will return to Lindenwood". bnd.
- Williams, Tim. "This Highland grad is quickly making a name for himself in the Pirates organization". bnd.
- "Geoff Hartlieb". The Baseball Cube. Retrieved May 17, 2019.
- "Prospect Hartlieb opening eyes during camp". MLB.com.
- RotoWire Staff (May 17, 2019). "Pirates' Geoff Hartlieb: Headed to big leagues". CBS Sports. Retrieved May 17, 2019.
- Nubyjas Wilborn (May 18, 2019). "Pirates opt for 'opener' — and it works in San Diego". Pittsburgh Post-Gazette. Retrieved May 19, 2019.