Celtic yesterday fired a warning shot across the bows of any footballer who seeks to break his contract under new Fifa guidelines by claiming that they will sue a player for damages should he walk away from Celtic Park before his contract has expired.

The warning was given by Peter Lawwell, the Celtic chief executive, who admitted that he was “intrigued” by Fifa’s increasingly infamous Article 17, whereby players can free themselves from their contracts, even with one, two or sometimes three years still to go.

Lawwell’s comments were particularly relevant to Artur Boruc, the Celtic goalkeeper, who is currently in talks with the club about an extension to his contract. The Pole is also said to be considering walking away from Celtic under Article 17’s precepts.

At 27, Boruc is halfway through a 4½year contract, but would be free under the Fifa legislation to leave Celtic Park next season for nothing, having served three years of his deal.

“Article 17 has to be very carefully considered,” Lawwell said. “The issue that has been thrown up is the Andy Webster case and no one yet knows how this Webster tribunal is going to go. But it appears that any player in the world may now have the right to break his contract: not the right to buy-out his contract, but to walk away from it.

“Let’s be clear: Celtic would sue any player who walks away under that scenario. If you are breaking an employment contract, you’ll be sued, and it is then the amount of damages which becomes the question. What of replacement value? What of incremental cost? What of lost opportunity? We would take these issues to a court of law, so it is not just a question of a player walking away.”

Article 17 allows a player under the age of 28 to walk away from his club after three years of his contract, or, for a player aged 28 or over, after two years. The ground-breaking case of Webster, who is being sued by Heart of Midlothian after walking out on them for Wigan Athletic, is currently at the Court of Arbitration.

Asked specifically about the £10 million-rated Boruc, Lawwell claimed that, having already instigated new talks with their goalkeeper, Celtic were in a strong position. The club, Lawwell argued, has Boruc under contract until 2010, if they so wish.

“Artur Boruc has a contract at Celtic until May 2009, and we have a unilateral option to have him for another year after that,” Lawwell said. “So we have Boruc here until May 2010. That is his contractual position.

“To reward Artur for his performances, we have approached him and said, ‘Let’s talk about improving your contract.’ And Artur said to us, ‘Fine, let’s talk.’ But my point is, there is no immediacy in this. We’ve got three years left on the deal. We are well ahead of the game with Artur.”

When pressed on the matter, though, Lawwell sounded a note of warning about the Boruc situation should the goalkeeper decide to go down the Article 17 route and leave Celtic. “Artur is 27,” Lawwell said. “He signed the contract with us when he was 25, in October 2005. After three years, under these [Article 17] rules, any player can move and be registered with another club. However, the player will have broken his employment contract, and the clubs will sue for damages, and the clubs will win. It will then just be the question of compensation to be decided.

“We are not unique. We are the same as any other club in the world. But in terms of Artur Boruc, we have done our work. We have got Boruc for another three years, notwithstanding the Andy Webster case, until 2010.”

Boruc has indicated that he is happy at Celtic, though the player has attracted the likes of Manchester United, Arsenal and Aston Villa with a string of superb performances.