Steven Whittaker's agent has claimed the versatile defender has rejected a new Rangers contract amid continued interest from Bursaspor.
Whittaker is heading into the final year of his contract at Ibrox and Rangers are attempting to fend off interest from Bursaspor.
The Scottish giants have already turned down three bids but the Turkish side have reportedly made a fourth offer for the 27-year-old Scotland international.
New Rangers boss Ally McCoist is determined to keep hold of a player he believes is integral to the squad.
But with Whittaker able to talk to other clubs about a free transfer in January, his agent, Ken Anderson, has called on Rangers to consider an offer from Bursaspor worth 750,000 euros (£664,424).
"He'll see out the final year of his contract and we'll talk to other teams in January if Rangers keep rejecting offers," he said.
"It's up to Rangers if they want to miss out on a transfer fee."
Anderson hinted that Whittaker did not feel that the new Gers offer reflected his worth to the club, adding: "They say they consider him to be one of their four main players."
Last week McCoist admitted the club had received a third offer for Whittaker but denied the player was for sale.
"I took a phone call from director Andrew Dickson to tell me about it," he said.
"He didn't even tell me the figures involved because I told him that I wasn't interested in selling Steven.
"I have made it clear that Steven is one of the players I see as part of my long-term plans for the club.
"That is why we have opened talks with his representatives to extend his current contract."