German club Hoffenheim have reportedly valued Gylfi Sigurdsson at around £10m.
The Icelandic international, who is currently on loan at Swansea City until the end of the season, has been linked with moves to Liverpool, Everton and Manchester United.
However, his parent club are not willing to let the coveted 22-year-old go without a fight, according to The Mirror.
Sigurdsson has scored seven goals in 16 appearances for the Swans this season.