Sky Sports sources understand Doncaster Rovers striker Billy Sharp has a £1.85million release clause in his contract which becomes effective on 1st January.
Sharp has been tipped to leave the Keepmoat Stadium when the transfer window reopens and Rovers chairman John Ryan had previously stated the forward would cost £3m.
However, it is understood that any club which offers £1.85m from New Year's Day will be able to hold talks with the former Sheffield United youngster regarding a possible deal.
The 25-year-old has scored nine goals for Championship strugglers Doncaster this season and has a string of suitors from the Premier League and second tier.
Fulham and Wigan Athletic are understood to be keen on Sharp, while Leicester City are also weighing up a move for the front-man.
Championship leaders Southampton remain interested after seeing a summer bid rejected, while Ipswich Town also failed with an offer before the window closed in August.
Hull City have been linked with a bid as well, but caretaker manager Nick Barmby cast doubt on the prospect of making a £3million offer for Sharp.