The Rangers boss revealed he may still be without Lee Wallace, Dean Shiels and Kirk Broadfoot in forthcoming games and is keen to add bodies to his group.
He said: "I've never said I was happy with my squad, far from it. We need numbers in and that's not just down to the poor performance today.
"We need players and I've said all along and we need to get them this week.
"Lee's struggling. His injury is taking a little longer than we'd hoped. Dean trained yesterday but wasn't quite fit enough to travel with the team.
"I don't know if they'll be ready for us on Thursday, and they are two bigger players for us but regardless of personnel, any Rangers team should be playing better than that.
"Kirk has a hamstring strain, which he's had since the Falkirk game so he was struggling with that too."
A similar problem meant Carlos Bocanegra was a doubt ahead of the game and that forced McCoist to include Greek debutant Antelis Argyriou on the unfamiliar left flank.
He added: "I thought he did well because we were unfair to him really to put him straight at left back because of personnel when he's a right sided player.
"The only thing we could have done was play Bocanegra at left back but he's had a hamstring problem too and we felt it was safer if he was more central with less strain on that.
"I thought he did well and he'll come on well and play better if and when we can get him on to the right hand side."