The Egyptian club have been asked to comply to a Cas order by the end of March or face dire consequences
World football governing body Fifa has issued African football giants Zamalek a "final warning" concerning their reluctance to pay Ghanaian striker Ben Acheampong an amount of over of $1 million (€827,575) for unfair treatment during a spell with the club between 2017 to 2018.
The five-time African champions risk being handed a transfer ban, deducted points or being demoted to the lower tier should they fail to honour a Court of Arbitration for Sport order by the end of March.
"Zamalek Sports Club is granted a final deadline of 30 days as from notification of the present decision in which to settle said amount," Fifa's Disciplinary Department wrote to the concerned parties on 1 March, the BBC has reported.
"Upon expiry of the aforementioned final deadline and in the event of persistent default or failure to comply in full with the decision within the period stipulated, a transfer ban will be pronounced until the complete amount due is paid.
"In addition, a deduction of points or relegation to a lower division may also be ordered in addition to a transfer ban in the event of persistent failure, repeated offences or serious infringements or if no full transfer could be imposed or served for any reason."
Acheampong claims his Zamalek predicament began following a managerial change at the club shortly after his arrival.
After being pushed to the periphery of the team, the 30-year-old pursued a loan move to Petrojet and was upon his return frozen out of the first team, leading to his decision to terminate his contract.
The Ghanaian believes the Egyptian club meted out the treatment on purpose, in a bid to force him to terminate his own contract and save the club from financial obligations should they be the one cutting short the deal.
"I feel great - great that the decision went in my favour for a second time," he told BBC Sport Africa at the time. "I feel vindicated. At the end of the day, the truth speaks.
"Now the decision is in my favour, I am desperate that Zamalek follow the instructions and pay the money as soon as possible. I am very, very happy."
According to Acheampong, he received only half of his financial entitlements ahead of his loan deal with Petrojet but Zamalek claims the player signed a contract, stating he would forfeit his salary while out on loan.
Again, the Ghanaian said he was compelled into an agreement indicating he had received all money owed him by Zamalek before the club would process paperwork needed by Fifa to approve a transfer to a Qatari side upon the termination of his contract.
"This is an important message from Fifa that they do not tolerate the abusive behaviour of Zamalek and Nader El Sayed," Roy Vermeer, a lawyer with global players' union Fifpro, told BBC Sport Africa.
"It's time that Zamalek starts engaging in a discussion with the player and his real legal representatives instead of playing tricks to get out of their obligations."
A former Ghana youth international, Acheampong played for Asante Kotoko during his time in his home league.