Sunderland are set to terminate the contract of defender Emmanuel Eboue after he was suspended by Fifa from all football-related activity for one year.
The 32-year-old, who joined the Black Cats until the end of the season on 9 March, was given the ban after failing to pay money owed to a former agent.
Sunderland boss Sam Allardyce said the club were “completely in the dark” over the dispute which started in July 2013.
“I’m massively disappointed like everyone else is,” said Allardyce.
The Sunderland manager added: “The problem is what has happened in the past has caught up with Emmanuel, for whatever the reason.
“He has got a ban and the contract gets terminated on that basis.”
Sunderland are 18th in the Premier League – two points from safety with eight games left – and face West Brom at the Stadium of Light on Saturday (15:00 BST).
Allardyce did suggest “there could be a way back” for Eboue, if he resolves the dispute. The Ivory Coast international has two weeks to appeal against the decision.
“He has relied on other people and other people have let him down,” added Allardyce.
Eboue, who has not made a first team appearance for the Black Cats, had been ordered by Fifa to pay agent Sebastien Boisseau an undisclosed amount he was entitled to under the terms of an agreement between the pair.
The former Arsenal full-back was fined 30,000 Swiss francs (£21,000) in September 2014 and given four months to settle the matter.
Eboue spent eight seasons at the Gunners after arriving from Belgian side Beveren in 2004, before moving to Turkey, where he won three Super Lig titles and five domestic trophies with Galatasaray.
He began training with Sunderland in February.
‘Fantastic news for agents’
Ghanaian football agent Oliver Arthur told BBC World Service that it was “very disappointing” that Eboue had got “into this mess”. He said the situation sometimes occurs when a player moves to a bigger agent and forgets to pay their previous representative.
Arthur said the ban was “fantastic” news for agents because it showed they can “take your case to a higher level”.
“Now it’s very easy to refer a player to a case like this and it’s easy for them to understand. A lot of players will now think twice in their decisions, think twice in keeping money and waiting to pay. Agents fees aren’t so big that players should get themselves into this mess.”
‘Losing Johnson will not affect dressing room’
Allardyce was speaking for the first time since ex-Sunderland winger Adam Johnson was jailed for child sex offences last week.
The 28-year-old had been allowed to continue to play for the club, before being sacked when he pleaded guilty to two offences at the start of his trial. He has lodged an appeal against his conviction for a third offence of sexual touching.
“We’ve lost a hugely talented player in Adam Johnson, irrespective of his indiscretions,” said Allardyce.
“He obviously got what he deserved, but we’ve lost a talented player I would’ve liked to keep. But it was taken out of our hands by other factors.”