Gallen was traded to the Miami Marlins in 2017 and made his MLB debut with the team in 2019. He was traded to the Diamondbacks midway through the 2019 season. In 2023, he was named the starting pitcher for the National League in the All-Star Game and helped the Diamondbacks reach the 2023 World Series.
Gallen was born on August 3, 1995, in Somerdale, New Jersey,[1] to Jim and Stacy Gallen.[2] When he was five years old, he refused to play tee-ball with his peers, instead demanding to play Little League Baseball with the Somerdale team; Gallen was taken in the third round of the Little League draft by his [3]father's team and would play with children between seven and nine years old.[4] At the age of 11, Gallen joined the Tri-state Arsenal Baseball Academy in New Jersey, where he served as a pitcher and second baseman.[5]
On December 14, 2017, the Cardinals traded Gallen along with Sandy Alcántara, Magneuris Sierra, and Daniel Castano to the Miami Marlins for Marcell Ozuna.[15] Gallen later speculated that the Cardinals traded him to the Marlins because he was reluctant to attend a winter workout camp.[16] He was a non-roster invitee to 2018 spring training.[17] He spent the season with the New Orleans Baby Cakes, going 8–9 with a 3.65 ERA and a 1.47 WHIP in 25 starts.[18] He returned to New Orleans to begin 2019.[19]
Gallen in 2020
On June 20, 2019, the Marlins promoted Gallen to the major leagues.[20] He made his debut that night in a start versus the Cardinals, recording six strikeouts and giving up one earned run over five innings pitched.[21]
On July 31, 2019, the Marlins traded Gallen to the Arizona Diamondbacks for shortstop Jazz Chisholm Jr.[22] In eight starts for Arizona, Gallen was 2–3 with a 2.89 ERA in 43+2⁄3 innings, striking out 53. In 2020, Gallen recorded 82 strikeouts in 72 innings. He also finished with an ERA of 2.75 and a 3–2 record.
Gallen returned to the Diamondbacks' rotation for 2022. Starting with an August 2 win over the Cleveland Guardians, he posted 34+1⁄3 consecutive scoreless innings before being named the National League (NL) Pitcher of the Month for August.[23] The scoreless streak continued until a September 11 win over the Colorado Rockies, totaling 44+1⁄3 innings. It broke Brandon Webb's club record of 42, achieved in 2007, and was the seventh-longest in major league history. During the streak, Gallen produced six consecutive games started without allowing a run, tying the major league record.[24] Gallen won the NL Player of the Week Award for the week of August 29 – September 4[25] and the NL Pitcher of the Month Award for August.[26] For the 2022 season, Gallen went 12–4 with a 2.54 ERA and 192 strikeouts in 184 innings. He finished fifth in NL Cy Young voting.[27][28]
On January 13, 2023, Gallen agreed to a one-year, $5.6 million contract with the Diamondbacks, avoiding salary arbitration.[29] He was named NL Player of the Week for the week of April 10–16.[30] He was named to the 2023 MLB All-Star Game.[31] Gallen pitched six no-hit innings in Game 5 of the 2023 World Series, but Arizona lost the series.[32] For the 2023 season, Gallen went 17–9 with a 3.47 ERA and 220 strikeouts in 210 innings. He finished third in NL Cy Young voting.
