Sunderland have revealed that Asamoah Gyan has not paid a donation to the club's foundation charity, which was written into his deal to join Al-Ain.
The 26-year-old secured a permanent move to the UAE earlier this month following his loan spell last season.
However, a club spokesman has now confirmed that Gyan has failed to make the £100,000 donation, despite earning a reported £10.4m last year.
"The donation has not been received to date, however we are hopeful that this is merely an oversight on the part of Asamoah and his representatives," said a spokesman.
"The Foundation does a tremendous amount of work with young people in the North East region and a donation of this kind will help to fund some fantastic programmes and support youngsters from some of the most vulnerable areas of society."
Gyan made 34 appearances for the Black Cats.