QPR were this morning assessing an injury Lee Wallace picked up against Birmingham.
The left-back limped off during the first half of Saturday’s goalless draw.
He is expected to miss Tuesday’s game at Barnsley along with George Thomas, who is still recovering from a thigh problem.
Mark Warburton said: “It looked a nasty one and Lee’s being assessed this morning. He’s with the medical team now.
“He tried to carry on. It’s one of those where you hope he’ll run it off, but you could see it was very troubling.
“We’ll see how he is this morning - see how he presents.”
Manager Warburton is hoping Thomas can establish himself in the attacking midfield role Luke Amos was playing in prior to suffering a knee injury.
But the Wales international, who has been out for a month, is not ready to play.
Warburton explained: “He’s not fit yet. You can’t have weeks out and then just come straight back into the first team.
“The trouble is that you lose a Luke Amos and then the games come thick and fast and the squad is light.
“Right now George is not available. You always want a player back but they have to be confident and the medical team have to be happy.”