Southampton signed Germany Under-21 defender Armel Bella-Kotchap from VfL Bochum in a deal worth a reported 10 million euros ($10.5 million) on Tuesday.
The 20-year-old has signed a four-year deal at St Mary’s after making 74 appearances for the German side.
France-born Bella-Kotchap helped Bochum win promotion to the Bundesliga in 2021 and made 26 appearances as they maintained their top tier status last season.
“He is a player who fits our profile very well and has a huge amount of potential, but with the number of senior games he has already played he can help us immediately,” Saints manager Ralph Hasenhuttl said.
“I think he has made the perfect choice in wanting to join us and we will now work with him to make sure he reaches his potential both for himself and for the team.”
Bella-Kotchap added: “I think, every young player dreams to play in the Premier League and I’m here and I’m happy and thankful for that.
“The coach has a big impact on me. We speak the same language and his interest was very big in me.”