The Blues striker aggravated the injury during the warm-up prior to the game against Queens Park Rangers at Loftus Road on 28th October. "It's great the lads are still doing well and we're where we should be, but I'm confident that I could be adding more spice to it if I was fit. "The thing I've got to do now is make sure I work hard during my rehabilitation so that I'm right for when the gaffer calls on me again. "The injury had been nagging a bit, I was feeling it in the Crystal Palace and Sheffield Wednesday games, but I wanted to keep on playing through the pain. "At QPR my groin tore, and the abductor muscle then ripped off the bone basically and I've had both sides fixed now. "It's one of those things, all part and parcel of being a footballer. I'll get on with it, get fit again and have no doubt the lads will keep doing all they can to keep winning matches in my absence.
Treatment on the injury has failed to see O'Connor recover and he has now undergone surgery and is expected to be sidelined for anything up to two months.
"It's very frustrating personally as I felt I had been contributing to the team and doing a good job," he told the Birmingham Mail on Thursday.
"It had to be done, so at least that should be the end of it and when I do come back, I won't have any problems.
"Hopefully I'll be back in action in no time at all and certainly involved in the business end of the season and the final push for promotion."