Dundee United boss Craig Levein has placed a £2million price tag on Celtic target Barry Robson.
Skysports.com understands Celtic have contacted United to register their interest in Robson as they look to bring the midfielder to Parkhead during this month's transfer window.
Robson is thought to have a buy-out clause in his contract, but Levein has warned all suitors the player will not be allowed to leave on the cheap and that he hopes to keep him at Tannadice.
"We've not had an offer for Barry and I hope we don't get one. We don't want to sell him," Levein told the Daily Record.
"We're looking to stay in the top six and get into at least one cup final and he's an important part of what we're doing here.
"People are only worth what others are willing to pay for them. When you see what others are going for and compare them to someone of Barry's ability, then I'd say he's worth £1.5m or even £2m.
"He's under contract for three more years and I have no indication that he wants to leave."
Meanwhile, United have completed the signings of Danny Grainger and Eric Odhiambo following the opening of the transfer window.
United have paid Gretna an undisclosed fee to secure the services of Grainger, while Odhiambo arrives at Tannadice on loan from Leicester until the end of the season.