Borussia Dortmund midfielder Christian Pulisic has joined Chelsea but will be loaned back to the German club for the remainder of the season, the Bundesliga club have announced.
Chelsea will pay £58million for the United States international, who has scored three goals in all competitions so far this term.
Pulisic’s contract with Dortmund was due to expire in 18 months.
“It was always Christian’s dream to play in the Premier League,” Dortmund’s sporting director Michael Zorc told the club’s official website.
“That certainly has to do with his American background and as a result we were unable to extend his contract. Because of this, we have decided to accept an extremely lucrative bid by Chelsea, given the low contract security.”
Pulisic, 20, joined Dortmund as a youth player in 2015 and has made over 100 appearances for the club.
"In the summer I move on to Chelsea and to a new competition, the English Premier League," Pulisic told Chelsea’s official website.
"It’s a privilege to have signed for such a legendary club and I look forward to working hard towards being a contributor to their team of world-class players."
It will raise serious doubts over the future of academy graduate Callum Hudson-Odoi, however, whose contract is set to expire in 18 months.
Hudson-Odoi has impressed during his limited periods on the pitch this season and has attracted plenty of interest from clubs around Europe.
Maurizio Sarri has expressed his desire to keep the highly-rated youngster at Stamford Bridge but Pulisic's summer arrival will only increase the competition for places.