The 27-year-old, an eight million euro signing from Juventus in 2005, is suffering from a blood clot in his knee which the club's doctors believe will rule him out for the rest of the season.

Due to the extent of the injury Fenerbahce have suspended Appiah's wages and the Turkish Football Association have accepted the club's decision.

Former Turkish national team doctor Mehmet Kurdog, who diagnosed Appiah's condition, said: "Treatment will immediately begin to dilute his blood.

"This will last for six months and during this period he shouldn't risk any contact that could cause bleeding to any part of his body.

"It is risky for him to head the ball as even this could cause a cerebral haemorrhage. There is a 95% chance that he will recover after the treatment and only a 5% chance of a recurrence of the problem. At the moment he can only do light training."

Appiah, who will also miss Ghana's African Nations Cup campaign in his home country, has only made six Super Lig appearances this season after undergoing knee ligament surgery in the summer.