Premier League strugglers Sunderland expect to learn in March if they will have to pay out £8m for a player they do not even own.
The Black Cats have been involved in a dispute with Inter Milan for more than a year over Argentina international Ricky Alvarez.
The player, now 28, headed for the Stadium of Light on loan in August 2014 with a view to completing a permanent transfer, which was to be triggered if they retained their Premier League status.
However, Alvarez's stay on Wearside was blighted by injury and, despite fending off relegation under Dick Advocaat, Sunderland pulled the plug on the proposed deal.
That decision has sparked a lengthy wrangle which resulted in a Court of Arbitration for Sport hearing in Lausanne earlier this month.
And final submissions are due in February before a decision is made.
Chief executive Martin Bain said: "It was meant to last a day - it didn't, it ran over.
"Submissions are now due in at the beginning of February and then I understand that, by the middle of March, there'll be a decision by CAS."
Should the decision go against Sunderland, they would face a €10m bill - around £8.4m - for a player who started just five Premier League games across his 17 appearances for the club.
The Black Cats' argument is that Inter's hesitation in sanctioning knee surgery for the player justified their decision not to honour the contract.
Alvarez was left without a club with neither Inter nor Sunderland requiring his services, and was eventually given special dispensation to join Sampdoria on loan in January, completing a permanent move as a free agent during the summer.