Star Brisbane midfielder Dayne Beams looks set to learn on Tuesday if his AFL season is over.
Surgery has not been ruled out for Beams but the Lions expect to learn the full extent of his knee injury when they receive scan results in the next 24 hours.
In just his second game of the season, Beams was forced off the field and missed the final quarter after copping a knock to his leg in their last-round 78-point Gabba loss to Collingwood.
Former All-Australian and Magpies premiership player Beams missed the first six rounds with knee tendinitis.
Meanwhile, captain Tom Rockliff looks set to miss Sunday's MCG clash with Melbourne due to a hamstring tear.
The Lions website said Rockliff was consulting a specialist with Lions head physio Shane Lemcke on Monday to get to the bottom of his recurring hamstring dramas.
His pre-season was hampered by a back related hamstring and calf problems before he suffered the tear against Port Adelaide a fortnight ago.