After participating in extended spring training, the Twins assigned Thorpe to the Cedar Rapids Kernels of the Class AMidwest League in June 2014, where he became the youngest player in the league.[7] He finished the year with a 3–2 win–loss record and a 3.52 ERA in 16 games started. At the end of the 2014 season, Thorpe was diagnosed with a sprained ulnar collateral ligament (UCL) in his pitching elbow.[8] He underwent Tommy John surgery to repair the injury in March 2015,[9] causing him to miss all of 2015 and 2016. Thorpe returned in 2017 and spent time with both the Fort Myers Miracle of the Class A-AdvancedFlorida State League and the Chattanooga Lookouts of the Class AASouthern League, pitching to a combined 4-4 record and 2.93 ERA in 17 total games (16 starts) between the two teams.[10] The Twins added him to their 40-man roster after the season.[11] Thorpe returned to Chattanooga in 2018, and was selected to represent the Twins in the All-Star Futures Game.[12]
On 28 June 2019, the Twins promoted Thorpe to MLB.[13] On 30 June, he made his MLB debut.[14]
On 29 June 2020, Thorpe made the Twins 60-man summer camp roster in 2020.[15] He made the Twins Opening Day roster in 2020.[16][17] In 2020, Thorpe registered a 6.06 ERA with 10 strikeouts in 16.1 innings pitched.[18] In 2021, Thorpe made 13 total appearances between Minnesota and the Triple-A St. Paul Saints. In 5 appearances for the big league club, logging a 4.70 ERA with 6 strikeouts in 15.1 innings of work.
In spring training in 2022, the Twins transitioned Thorpe to a relief pitcher.[19] On 28 March 2022, the Twins sent Thorpe outright to the St. Paul Saints of the Triple-AInternational League, removing him from their 40-man roster to make room for the newly-signed Chris Archer.[20] On 21 April 2022, the Twins released Thorpe, making him a free agent.[21]