Aberdeen boss Jimmy Calderwood fears January signing Craig Brewster has dislocated his shoulder.
The former Dundee United player-manager fell awkwardly just before half-time of Saturday's 1-1 home draw with another one of his former clubs in Inverness Caledonian Thistle.
The 40-year-old is facing up to six weeks on the sidelines as a result of his misfortune, with Calderwood also confirming the loss of Jamie Smith and Zander Diamond to groin injuries.
"The way it is looking at the moment is that Craig has dislocated his shoulder and could be out for four to six weeks," 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."
The trio's injuries are a blow to The Dons, with Calderwood unsure if he can reinforce his Pittodrie squad during this month's transfer window.