In January 2015, Thommy was loaned to 2. Bundesliga club 1. FC Kaiserslautern for a year and a half until summer 2016. However, at the occasion of announcing his loan, FC Augsburg's general manager Stefan Reuter stated that Thommy still was a component of their future plans. Thommy was contracted with Augsburg until 2018.[4] The loan was ended on 31 January 2016.[5]
Jahn Regensburg (loan)
In the 2016 summer transfer window, he was loaned out again, this time to SSV Jahn Regensburg.[6][7] He made his league debut and first start for Regensburg on 30 July 2016 in a 2–0 home victory over F.C. Hansa Rostock. He was subbed off in the 82nd minute, being replaced by Uwe Hesse.[8]
Stuttgart
On 18 January 2018, Thommy moved to VfB Stuttgart.[9] His debut and first competitive start for Stuttgart came on 3 February 2018 in a 1–1 away draw against VfL Wolfsburg.[10] He scored his first Bundesliga goal on 24 February 2018 against Eintracht Frankfurt. On 19 August 2018, Thommy extended his contract with VfB Stuttgart until June 2022.[11]
On 28 May 2022, Stuttgart announced that they would not extend Thommy's contract beyond the 2021-22 Bundesliga season.[12]
Düsseldorf (loan)
On 10 July 2019, Fortuna Düsseldorf announced the signing of Thommy on loan until the end of 2019–20 season with an option to buy him permanently.[13]
Sporting Kansas City
On 23 June 2022, it was announced that Thommy had signed with Major League Soccer side Sporting Kansas City on a deal until the end of the 2024 season.[14] Thommy debuted for Kansas City on 23 July 2022, starting in a 0-2 loss to Los Angeles FC.[15]