Southampton have signed defender Armel Bella-Kotchap from Bochum for about 10m euros (£8.6m).
The 20-year-old, who has signed a four-year contract, played 74 times for the Bundesliga club.
He made 26 appearances as he helped Bochum win Bundesliga 2 and promotion to the German top flight in 2021.
"He is a player who fits our profile very well and has a huge amount of potential," said Southampton manager Ralph Hasenhuttl.
"But, with the number of senior games he has already played, he can help us immediately.
"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."
The Germany Under-20s international made 22 appearances last season as Bochum secured their Bundesliga status by finishing 13th.
"I think, every young player dreams to play in the Premier League and I'm here and I'm happy and thankful for that," said Bella-Kotchap.
"The coach has a big impact on me. We speak the same language and his interest was very big in me.
"The club convinced me and said they want to make a project with me and I'm ready to go and I will fight for my place."
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