St Mirren are set to go into Saturday's trip to Hamilton with only one recognised centre-back after Gary MacKenzie picked up a hamstring injury against Motherwell.
The defender limped off early in the 3-0 defeat with what appeared to be a serious hamstring problem.
Saints were already missing Kirk Broadfoot with a foot injury and right-back Paul McGinn had to move inside to partner Sean McLoughlin.
Manager Jim Goodwin said: "It's a hamstring injury so Saturday will definitely be too soon. You are looking at least a couple of weeks, that's probably the quickest turnaround but hamstring injuries can be anything up to six weeks. Hopefully it's not as bad as we fear.
"Saturday will probably come too soon for Kirk and Sam (Foley) was missing on Wednesday night as well. Sam has been a massive player for us, he has been consistent throughout the season up until now, played every game, and unfortunately picked up a hamstring injury on Saturday up at Aberdeen.
"He is one that we hope will make the weekend because he makes a big difference to us in central midfield."
