Asamoah Gyan was stretchered off during Al Ahli’s 0-2 loss to Al Jazira on Saturday.
The Ghanaian striker appeared in serious discomfort after landing awkwardly just 17 minutes into the game.
Gyan’s knee appeared to buckle, with his ankle giving way as Al Ahli players and fans feared the worst.
He was replaced by UAE striker Waleed Hussain, who has lost his place since Gyan’s arrival.
Gyan will undergo further tests on Monday to ascertain the extent of injury.