Aberdeen boss Jimmy Calderwood said Craig Brewster could be out for six weeks after suffering an injury in the 1-1 draw with Inverness CT.
The veteran striker, 40, suffered a dislocated shoulder during Saturday's SPL clash at Pittodrie.
"The way it is looking at the moment is that Craig has dislocated his shoulder and could be out for four to six weeks," said Calderwood.
Jamie Smith and Zander Diamond are also out injured for a similar period.
Calderwood said: "Jamie Smith is out for six to eight weeks with a groin injury and Zander Diamond needs an operation on a groin which will keep him out for the same length of time as Jamie."
Aberdeen needed a last-minute equaliser from Steve Lovell to rescue a point against Inverness - and Calderwood said the striker had given him a selection headache.
"We looked down and out, but Steve has saved us again and it could be a massive goal come the end of the season," he said.
"We have come back against a team who are very difficult to play against and it is a real plus point if you can look at the bench and bring Lovell on with his pace.
"He is scoring goals for fun whenever he comes on and he is giving the manager a real problem."