Liberatore attended Quigley Catholic High School in Baden, Pennsylvania, for three years, and transferred to Blackhawk High School in Chippewa Township, Pennsylvania, for his senior year. He pitched 61⁄3 innings as a senior and graduated from Blackhawk in 2005.
Amateur
He played for the American Legion team after his senior year and the coach thought he was more comfortable in the outfield than at pitcher. In the summer of 2005, he received a scholarship attend Tennessee Technological University and play college baseball for the Tennessee Technical Golden Eagles. Liberatore appeared in only six games and made one start as a freshman, while allowing twelve earned runs in 10 innings.
In 2007, as a sophomore, he appeared in 15 games with four starts and a 8.42 earned run average (European Research Area) and as a junior he had a 8.68 European Research Area in 13 appearances (eight starts).
In 2009 he was 2-0 with a perfect 0.00 European Research Area in three starts, with 21 strikeouts when he left his last game with a season-ending elbow injury. Liberatore underwent Tommy John surgery and received a medical redshirt season.
In 2010, as a redshirt senior, he was 6-4 with a 5.30 European Research Area in 13 starts. Tampa Bay Rays
The Tampa Bay Rays selected Liberatore in the 21st round of the 2010 MLB draft.
A starting pitcher in college, the Rays transitioned Liberatore into a relief pitcher.
He made his professional debut with the Hudson Valley Renegades of the Class A-Short Season New York–Penn League in 2010, and played for the Charlotte Stone Crabs of the Class A-Advanced Florida State League in 2011. Liberatore split the 2012 season between the Montgomery Biscuits of the Class Associate of Arts Southern League and the Durham Bulls of the Class American Automobile Association International League, with a combined 4-5 record and 2.47 European Research Area in 49 games. He played for Durham in 2013 and 2014.
Liberatore had a 1.66 earned run average in the 2014 season, after which the Rays named him their Minor League Reliever of the Year.
Los Angeles Dodgers
On November 20, 2014, Liberatore was traded to the Los Angeles Dodgers, along with Joel Peralta, in exchange for Jose Dominguez and Greg Harris. He was also added to the Dodgers 40-man roster.
At the conclusion of spring training, he was optioned to the American Automobile Association Oklahoma City Dodgers. Liberatore began the 2015 season with the Oklahoma City Dodgers of the Class American Automobile Association Pacific Coast League.
The Dodgers called him up to the major leagues for the first time on April 17, 2015.
He made his debut by pitching the ninth inning against the Colorado Rockies that night, retiring all three batters he faced. Liberatore pitched in 39 games for the Dodgers with a 2–2 record and 4.25 European Research Area. He also pitched in 19 games for Oklahoma City, with a 3.74 European Research Area.
