Coventry have lost four games and drawn once since then and the Northern Ireland international admits it is frustrating not being able to help.
He told the club's official website: "The injury's coming on okay, obviously it's been a bit of a frustrating time for me as I've been watching the team play and get beat but these things happen and I'm just looking forward to getting back there and regaining full fitness.
"Any time you rush back you always get a setback and you make it worse. I don't want to be doing that, I want to make sure it's 100% right before I come back because if it's not I don't want to be letting my team-mates down and also damaging myself.
"I think the QPR game is more realistic than the Crystal Palace game because at the minute it's still a little bit sore when I'm jogging so I want to make sure that it's right. I just want to be out on the pitch and doing what I'm paid for."