Sporting Lisbon are refusing to take back Yannick Djalo after the Court of Arbitration for sport ruled his transfer to Nice was invalid.
The Portuguese club thought they had concluded a deal to sell the striker to the Ligue 1 outfit on summer deadline day, but it was later revealed the two clubs had failed to complete the transfer in time.
Nice chairman Julien Fournier has announced the player would be returning back to Portugal as he has a contract with Sporting that runs until 2013.
Despite the court ruling, Sporting are refusing to accept the player still belongs to them.
"He is no longer a Sporting player," a club official was quoted as saying in the Record newspaper.
"The Yannick problem is now Nice's concern, so it's up to them to sort it out.
"We signed a transfer agreement with Nice and we hope it will be respected."