Amateur career

After graduating from Clay High School in Green Cove Springs, Florida, Dunning attended the University of Florida, where he played college baseball for the Florida Gators.^[1][2] Dunning appeared in 17 games as a freshman, finishing the year with a 4.50 ERA. His sophomore year, Dunning began starting more games, as opposed to the reliever role he had his freshman year, finishing the year with a 4.03 ERA in 16 appearances, 14 of which were starts. As a junior, Dunning returned to the bullpen, the role he predominantly had his freshman year. Dunning appeared in 33 games, only five of which were starts, and had a 2.29 ERA. In the 2016 NCAA Division I baseball tournament, Dunning pitched 15.1 innings, giving up only one run.^[3]

Washington Nationals

After his junior year, he was drafted by the Washington Nationals in the first round of the 2016 MLB draft.^[4] He split time during his first professional season between the Gulf Coast League Nationals and the Auburn Doubledays where he posted a combined 3–2 win–loss record and a 2.02 earned run average (ERA) in eight games between both teams.

Chicago White Sox

On December 7, 2016, the Nationals traded Dunning, Reynaldo López, and Lucas Giolito to the Chicago White Sox for Adam Eaton.^[5] For the 2017 season, the White Sox assigned Dunning to the Kannapolis Intimidators, and after he posted a 0.35 ERA in 26 innings, promoted him to the Winston-Salem Dash, where he spent the rest of the season, posting a 6–8 record and 3.51 ERA in 22 games started.^[6] Dunning spent 2018 with both Winston-Salem and the Birmingham Barons, pitching to a combined 6–3 record and 2.71 ERA in 15 starts between both teams.^[7]

Dunning underwent Tommy John surgery on March 18, 2019, after suffering a torn ulnar collateral ligament. His surgery was performed by James Andrews.^[8] Dunning missed the entire 2019 season.^[8] Dunning was added to the White Sox 40–man roster following the 2019 season.^[9]

Dunning was called up to the active roster and made his MLB debut on August 19, 2020, striking out seven batters with just one walk in 41⁄3 innings in a 5–3 victory over the Detroit Tigers.^[10][11][12] With the 2020 Chicago White Sox, Dunning appeared in seven games, compiling a 2–0 record with 3.97 ERA and 35 strikeouts in 34 innings.^[13]

Texas Rangers

On December 7, 2020, Chicago traded Dunning and Avery Weems to the Texas Rangers in exchange for Lance Lynn.^[14] On June 1, 2021, Dunning recorded his first major league hit, a single off of Colorado Rockies starter Germán Márquez. Dunning finished the 2021 season after posting a 5–10 record with a 4.51 ERA and 114 strikeouts over 117+2⁄3 innings.^[15]

Dunning went 4–8 with a 4.46 ERA and 137 strikeouts over 153+1⁄3 innings for Texas in 2022. He underwent surgery to repair a torn labrum in his right hip at the end of that September, causing him to miss the end of the season.^[16]