The 23-year-old goalkeeper originally joined VfB on loan from TSG Hoffenheim for a year in summer 2019, with the move later made permanent. He made his VfB debut at home to Hannover 96 on 26 July 2019, and he went on to play a crucial role in the successful 2019/20 promotion campaign, keeping 11 clean sheets in 31 Bundesliga 2 matches.
Last season, Kobel made 33 Bundesliga appearance plus one more in the DFB Cup, with another six clean sheets during that time.
VfB Stuttgart would like to thank "Greg" for his commitment to the club and wish him all the very best for the future both on and off the pitch.
Sporting director Sven Mislintat: "Gregor more than fulfilled the expectations we had in him when he joined us and he has gone on to become one of the best goalkeepers in the league. His move to Borussia Dortmund is a genuine win-win situation, because Gregor will be able to take his career to the next level with a Champions League club, while we at VfB will be generating some important income in what are clearly tough times economically. We’d like to thank Gregor for his time with us and wish him all the best for the future."
Gregor Kobel: "I’ve had two exciting and successful seasons in Stuttgart and I got to experience just how deeply rooted the club is in Stuttgart and the whole region. Thank you so much to all the VfB fans for the great support I always got, and also to my teammates for two brilliant years!"