Manchester United have now joined the pursuit for highly-rated 20-year-old Christian Pulisic, according to Sport Bild.
The midfielder has been linked with Chelsea and Liverpool have already been linked with a move for the USA international.
However, Jose Mourinho will be desperate to add players as his side are currently seventh in the Premier League.
In-form Jadon Sancho has nabbed Pulisic's place in the starting XI and the player himself has dropped hints that he might push for a move away from the German giants.
"I'm still focused on Dortmund. We are doing great this season," the 20-year-old told NBC Sports.
"Once the break comes (in January) that is always when I will have to discuss with Dortmund and see about my future."
While also recently saying: "England, the Premier League, is a league where lots of kids dream of playing. So there is no reason why maybe one day I won't play here."
However, Dortmund's sporting director Michael Zorc has ruled out selling Pulisic until at least the end of the season.
The midfielder has been at Dortmund since he was 16-years-old and has already made over 100 appearances for BVB, while he has also already captained the USA national side.
The youngster is valued at roughly £53million by the club and has just 18 months left on his contract.
Meanwhile, Chelsea are understood to be leading the race as they odds-on (4/7) to sign the player by the end of the January transfer window.