Artur Boruc has warned Celtic that his desire to stay at Parkhead may wane as he waits on a new contract offer.

The Poland goalkeeper is tied to the club until summer 2009 and both parties have the option of a one-year extension.

But reports claim the 27-year-old is considering following the route Andy Webster took to leave Hearts a year before his contract expired.

Boruc said: "I'm waiting for Celtic's directors to make me an offer.

"I want to stress I am happy here but things can change quickly in football."

Webster was the first player to invoke article 17 of FIFA's transfer regulations, which allows a player to buy-out his contract if he has already served three years.

But the ramifications of his pioneering move are still unknown following a hearing at the Court of Arbitration for Sport earlier this month.

The Scotland defender left Hearts in May 2006 and is now on loan at Rangers from Wigan.

FIFA ruled he had breached his contract without just cause and ordered him to pay £625,000 to Hearts, a fee Wigan had promised to pay.

But Hearts appealed, claiming they should receive more than #4million, and a ruling is not expected until the end of November.