Alan Gow's proposed move to Wolverhampton Wanderers has fallen through after the midfielder failed a medical.
The Championship leaders had agreed a fee of around £250,000 with the Scottish giants for Gow, who had been on loan at Blackpool.
Wolves boss Mick McCarthy is known to be a long-standing admirer of Gow, having had a bid rejected by the 25-year-old's former club Falkirk before his move to the Old Firm club.
McCarthy said: "We'd agreed everything with him and it was fine, but something has shown up in the medical which we are not completely happy about and he's gone back up there to get it checked out.
"I don't know what will happen in the future, but it's not going to happen in this window."
Gow made just two appearances for Walter Smith's side since his move to the club in June 2007, but scored five goals in 17 outings for Blackpool this season.