Fabricio Coloccini has been informed he will face legal action if he carries out his threat to walk out of Newcastle during the transfer window.
Coloccini told Newcastle officials on Wednesday he would not play for the club again after prolonged talks to broker a solution to his desire to leave this month had broken down.
The 31-year-old is desperate to return to Argentina and first informed the club of his intention on 10 January. That was forcibly reaffirmed on Wednesday, and at that point the central defender seemed set to carry out his threat to leave St James' Park, where he has played since he first moved from Deportivo La Coruna in 2008 for £10.3 million.
Newcastle executives, backed by club owner Mike Ashley, have warned the player that any breach of his contract will lead to a legal fight, and their position is strong, given that Coloccini signed a new, four-year contract last year to extend his time in the North-east.
In recent months Coloccini has sought to return to his native country for personal reasons, and had hoped his current club would take that into consideration, and allow him to return to Argentina, where his wife is believed to have headed.
However, Newcastle and Ashley have stood firm in their position that they would not allow the player to leave on a cheap deal and have told the player it will cost him £7m to buy out his contract.
Coloccini returned to training this morning, and while his future remains to be fully clarified, that alone, was a surprise.
Newcastle have continued their dramatic player recruitment drive. Striker Yoan Gouffran was unveiled as a £1.3m signing from Bordeaux and late in the afternoon, Massadio Haïdara signed a five-and-a-half-year deal. The fee to bring him from Nancy is expected to be around £2.5m.
"It was the desire of the club to sign me up which was the most important factor," Haïdara said. "It was nothing to do with the league position. It was really all about the club's desire and willingness to sign me up.
"Also, I like the club's ambition to strengthen the whole team so we can improve our league position. That's what appealed to me so I didn't hesitate."
Moussa Sissoko is also expected to sign today from Toulouse, with Newcastle pushing for the 22-year-old to join immediately. The France midfielder had been chased by both Queen's Park Rangers and Aston Villa.
Newcastle have also made a €3m (£2.5m) bid for Bastia's 19-year-old midfielder Florian Thauvin. However Thauvin is thought to favour a move to Lille.
Gouffran, who could make his debut at Villa on Tuesday, believes he will be able to replace Demba Ba. "What's my big assets?" he said. "Speed. I'm fast and I score goals. Can I score as many as Demba Ba? Yes. I'm a centre-forward. I have proven that I can score goals in France. It will be different in the Premier League and it is up to me to make sure I go on the pitch and score and do everything I can to succeed in the Premier League, a different country."