Liberatore appeared in only six games and made one start as a freshman, while allowing twelve earned runs in 10 innings.[3] In 2007, as a sophomore, he appeared in 15 games with four starts and an 8.42 earned run average (ERA)[3] and as a junior he had an 8.68 ERA in 13 appearances (eight starts).[3] He participated in the Valley Baseball League over the summer between his junior and senior seasons and won the pitcher of the year honors while leading the league with a .170 batting average against.[4] In 2009, he was 2-0 with a perfect 0.00 ERA in three starts, with 21 strikeouts[3] when he left his last game with a season-ending elbow injury.[4] Liberatore underwent Tommy John surgery[5] and received a medical redshirt season.[4] In 2010, as a redshirt senior, he was 6-4 with a 5.30 ERA in 13 starts.[3]
Liberatore began the 2015 season with the Oklahoma City Dodgers of the Triple-A Pacific Coast League. The Dodgers called him up to the major leagues for the first time on April 17, 2015.[11] He made his debut by pitching the ninth inning against the Colorado Rockies that night, retiring all three batters he faced.[12] Liberatore pitched in 39 games for the Dodgers with a 2–2 record and 4.25 ERA.[13] He also pitched in 19 games for Oklahoma City, with a 3.74 ERA.[7]
On July 9, 2016, Liberatore set a Dodgers franchise record with his 24th consecutive scoreless appearance, breaking the mark previously set by John Candelaria in 1991.[14] In 2016, he appeared in 58 games with a 3.38 ERA.[13] He underwent left elbow debridement surgery after the season.[15]
Liberatore was again optioned to Oklahoma City to begin the 2017 season.[16] After pitching in six games in the minors, he was recalled to the Dodgers on April 23.[17] He was sidelined with a groin injury in May[18] and then came down with left forearm tightness shortly afterwards.[19] That injury wound up keeping him on the disabled list for the rest of the season.[20] He only pitched 31⁄3 innings over four games for the Dodgers in 2017, allowing one run on three hits.[13]
On May 4, 2018, against the San Diego Padres at Estadio de Béisbol Monterrey, Liberatore was one of four pitchers involved in a combined no-hitter as the Dodgers won 4–0, pitching the ninth inning to finish off the game.[21] The Dodgers designated him for assignment on August 31, 2018[22] and released him on September 5.[23] In 17 major league games in 2018, he allowed four earned runs in 13 innings for a 2.77 ERA.[13]
