Celtic insist any transfer request from Bulgarian midfielder Stilian Petrov will be rejected.
The 26-year-old has been strongly linked with a move away from Glasgow despite signing a new deal in January which committed him to the club until 2010.
Petrov joined the Hoops in 1999 and, after initially failing to settle, has since gone on to become an integral part of the team.
But, after a reported fall-out with manager Gordon Strachan, speculation has intensified over the future of Petrov.
A Celtic spokesman said: "We have received no official transfer request from Stilian Petrov, who has recently signed a new long-term contract with the club, but clearly, any such request would be rejected."
Petrov has previously attracted the attention of Everton and Fulham in the Barclays Premiership. The former CSKA Sofia player enjoyed a starring role under previous Celtic boss Martin O'Neill.
He won three SPL titles during O'Neill's tenure and appeared in the 2003 Uefa Cup final extra-time defeat to Porto.