O'Neill said: "We have a couple of days to add someone if we can. After February 1 that is it so we will see what we can do.
"If it didn't materialise I'd be somewhat disappointed, I'd be worried because if anything happened to Steven Fletcher which could cause us a problem. I don't do relaxed but I'm still genuinely hopeful we can add to the squad and I think we can get someone else in.
"In terms of trying to get a bit more forward power, I think it's fair to say that is what we'll be looking at. We are linked with quite a few players and we will try and get someone in if we can. We are going to try and do something about it.
"I would like to try and improve it if we can but that is not always that easy. If we are left with this squad then we have to try and manage it as best we can but I am still hoping we can do something."