Burnley will be holding out for a mammoth fee for Michael Keane as reports claim they will owe Manchester United 20percent of any fee.
Leicester City failed with at least one bid for the defender in the summer as Burnley managed to fight off their interest, but Chelsea are also in the hunt and will make a move in January.
The Clarets signed Keane from United for what looked to be a bargain fee of £2.5million back in 2014, but it has now been revealed United covered themselves by insisting on the sell-on clause.
Keane's stock has risen even further after he was called up into the England squad this week and Burnley are desperate to get him tied down to a new deal asap.
If Chelsea do go back in they will have to start the bidding at £25million, which would mean £5million would line the pockets of Manchester United.
Liverpool are also said to be in the hunt and Burnley will be hoping a bidding war could push the price up even further.