Clarkin was drafted by the New York Yankees 33rd overall in the 2013 MLB Draft out of James Madison High SchoolinSan Diego, California. On June 17, 2013, the Yankees signed him with a slot-money deal worth $1,650,100.[1] He made his professional debut that season with the GCL Yankees where he pitched to a 10.80 ERA in five innings. In 2014, he was considered the team's 8th best prospect, according to MLB.com.[2] Clarkin played for the Charleston RiverDogs where he pitched to a 3–3 record and 3.21 ERA in 16 games (15 starts) along with playing one game for the Tampa Yankees at the end of the season. He missed the entire 2015 season due to an elbow injury.[3] He returned in 2016 and pitched for Tampa, posting a 6–9 record, 3.31 ERA, and 1.33 WHIP in 18 starts. He suffered a meniscus tear in his knee that required surgery, ending his season in July.[4] Clarkin began 2017 back with Tampa, missing three weeks to shoulder soreness.[5]
Clarkin was traded on July 18, 2017, along with Tyler Clippard and Blake Rutherford in exchange for Todd Frazier, David Robertson, and Tommy Kahnle.[6] Chicago assigned him to the Winston-Salem Dash and he finished the season there. After one start, he suffered an oblique strain.[7] When he returned, Clarkin introduced a cutter in order to generate more ground balls.[8] In 18 games (17 starts) between Tampa and Winston-Salem, he was 4–5 with a 2.60 ERA.[9]
The White Sox added him to their 40-man roster after the 2017 season.[10] He pitched the majority of the 2018 season with the Double-ABirmingham Barons, making 18 appearances (10 starts) and finishing with a 4–5 record and 5.64 ERA over 68.2 innings pitched. He missed a month of playing time to a groin strain and was briefly demoted to High-A.[11]
After the 2018 season, the White Sox designated Clarkin for assignment, and he was claimed off waivers by the Chicago Cubs on November 20.[12] On November 26, he was claimed back off waivers by the White Sox.[13] The White Sox designated Clarkin for assignment again on January 8, 2019, and the Cubs claimed him on January 16.[14] On February 1, he cleared waivers and was outrighted off the 40-man roster.[15] Clarkin attended big league spring training as a non-roster invitee.[16] He appeared in 10 games for the Double-ATennessee Smokies, posting a 0–0 record and 3.38 ERA. After missing time to two separate injuries, he was released on June 21, 2019.[17][18]
On March 4, 2020, Clarkin signed a minor league contract with the San Diego Padres.[19] He did not play in a game in 2020 due to the cancellation of the minor league season because of the COVID-19 pandemic.[20] Clarkin was released by the organization on May 27.[21]
In July 2020, Clarkin signed on to play for Team Texas of the Constellation Energy League (a makeshift 4-team independent league created as a result of the COVID-19 pandemic) for the 2020 season.[22]
On November 24, 2020, Clarkin signed a minor league contract with the Colorado Rockies organization.[23] He split the 2021 season between the Double-A Hartford Yard Goats and the Triple-A Albuquerque Isotopes, struggling immensely to a 3-7 record and 7.86 ERA with 32 strikeouts in 68.2 innings pitched. He elected free agency following the season on November 7, 2021.[9]
On February 3, 2023, Clarkin signed a minor league contract with the Seattle Mariners organization after a year of inactivity.[24] He was released by the Mariners on March 31.[25]
On April 10, 2024, Clarkin signed with the Charros de Jalisco of the Mexican League.[27] In 6 appearances for Jalisco, Clarkin logged a 5.40 ERA with 6 strikeouts across 5 innings pitched.
On April 28, 2024, Clarkin signed a minor league contract with the Arizona Diamondbacks.[28] In 6 games for the Triple–A Reno Aces, he struggled to a 10.00 ERA with 12 strikeouts across 9 innings pitched. On May 30, Clarkin was released by the Diamondbacks organization.[29]
