O'Hara returned from injury too early
The former Tottenham Hotspur man underwent surgery during December and made his comeback last month in order to aid the club's battle against relegation.
However, he acknowledges he has been unable to do himself justice after confessing he has been playing with the help of painkilling injections.
O'Hara missed the weekend’s 5-0 thumping at the hands of Manchester United and insists he will not return to action until he is 100 percent fit.
"Since I've come back from it [the injury], I've had to have injections for games and haven't been able to train," he said on his personal Twitter account.
"I haven't been able to play at the levels I expect from myself so I've decided until I'm 100 percent in my groins then I'll be out.
"I probably came back too early [because] I was so desperate to play and help the team."