Partizan Belgrade have warned Chelsea off defender Stefan Savic.
Chelsea, in the grip of a defensive shortage, have kept tabs on the 6ft 1in centre half who impressed in Montenegro's goalless draw against England at Wembley last month.
Amid other interest from Roma and CSKA Moscow, Shakhtar Donetsk were understood to be favourites to clinch his signing by preparing a £6.75million bid.
But Partizan president Dragan Djuric said: "Savic is not for sale. He will stay with this club for at least two years. He is the future of Partizan so we don't want to sell him. Not even for 10million (£8.5m)."