The Winter Transfer window is officially opened and Chelsea are the ones to make the first 'big' January signing.

Borussia Dortmund have confirmed that one of the biggest young prospect in world football presently, Christian Pulisic has joined the Blues

The deal that takes the American teenager to Chelsea is believed to worth about £63 million.

Pulisic will be loaned back immediately to Dortmund and he will continue in Germany till the end of the current season, before moving to Chelsea.

 The 20-year-old is still considered one of the most brightest talents in world football, despite seeing Jadon Sancho replace him in the Dortmund first XI.

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Dortmund have confirmed the move in a statement released on Wednesday morning having been unable to agree a new deal with the 20-year-old who will now complete a “dream” move to the Premier League.

"It was always Christian's dream to play in the Premier League. That certainly has to do with his American background, and as a result we were unable to extend his contract,” Dortmund sporting director Michael Zorc said.

"Against this background, we have decided to accept an extremely lucrative bid by Chelsea, given the low contract maturity."

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