Leibrandt signed and spent 2014 with the GCL Phillies and Williamsport Crosscutters, pitching to a combined 3–5 record and 2.82 ERA with 67 strikeouts and an 0.97 WHIP in 60.2 innings. In 2015, he played for the Clearwater Threshers where he compiled a 7–3 record, 3.11 ERA and 1.03 WHIP in 17 starts. He was a Florida State League Mid-Season All Star, and an MiLB Phillies Organization All Star. In 2016, he returned to Clearwater, but pitched in only six games due to injury. He spent 2017 with both the Reading Fightin Phils and Lehigh Valley IronPigs, posting a combined 11–5 record and 3.62 ERA in 25 total starts between the two clubs.[5][6]
Leibrandt returned to Lehigh Valley in 2018, going 4–1 with a 1.42 ERA and an 0.87 WHIP in 20 games (six starts), and struck out 32 batters in 50.2 innings.[7][8] He last pitched on June 30, and underwent Tommy John surgery, missing the remainder of the 2018 season and the 2019 season.
The Phillies released Leibrandt on May 29, 2020.[9][10]
On August 10, 2020, the Miami Marlins selected Leibrandt's contract from Somerset.[14] Leibrandt was promoted to the major leagues on August 18.[15] He made his major league debut on August 23 against the Washington Nationals. On the season, Leibrandt appeared in five big league games, notching a 2.00 ERA with three strikeouts in 9 innings pitched. He was removed from the 40–man roster and sent outright to the Triple–A Jacksonville Jumbo Shrimp on October 29, and became a free agent on November 2.[16]
On April 5, 2021, Leibrandt re-signed with the Marlins on a minor league contract.[17] Leibrandt split the season between Jacksonville and the Double–A Pensacola Blue Wahoos, posting a cumulative 5.68 ERA with 74 strikeouts in 88+2⁄3 innings of work across 21 games. He elected free agency following the season on November 7.[18]
On March 16, 2022, Leibrandt signed a minor league contract with the Chicago Cubs.[20] Leibrandt split time between the Double–A Tennessee Smokies and Triple–A Iowa Cubs, pitching to a cumulative 4–4 record and 4.67 ERA with 68 strikeouts in 69+1⁄3 innings of work across 21 games (8 starts). He was released by the Cubs organization on August 5.
High Point Rockers
On April 28, 2023, Leibrandt signed with the High Point Rockers of the Atlantic League of Professional Baseball.[21] He made 3 starts for the Rockers, posting a 5.40 ERA with 9 strikeouts in 11+2⁄3 innings pitched. Leibrandt was released by the team on May 14.[22] On July 31, Leibrandt re–signed with the Rockers.[23] He totaled a 3.26 ERA with 53 strikeouts across 12 starts for the club in 2023.
On April 19, 2024, Leibrandt re–signed with the Rockers.[24] In 4 starts for the club, Leibrandt compiled an 0.93 ERA with 24 strikeouts across 19+1⁄3 innings pitched.
Cincinnati Reds
On May 24, 2024, Leibrandt's contract was purchased by the Cincinnati Reds organization.[25] In 15 starts for the Triple–A Louisville Bats, he registered a 3–4 record and 4.46 ERA with 63 strikeouts across 72+2⁄3 innings of work. On August 29, the Reds selected Leibrandt's contract, adding him to their active roster. He made his Reds debut that same day, pitching 2+1⁄3 innings of scoreless relief in a Reds win.[26] Leibrandt was designated for assignment by Cincinnati on October 28.[27] He cleared waivers and elected free agency on October 30.
New York Yankees
On November 8, 2024, Leibrandt signed a minor league contract with the New York Yankees organization.[28]