Ince had looked likely to add O'Hara to his squad for the remainder of the year, but the former England international has insisted that he would have been unable to use the 27-year-old in his starting lineup.
The 46-year-old told The Gazette: "He's probably not fit enough yet. We might go back in for him in January. He needs another couple of weeks' fitness and that's the problem that we had.
"He's still a good player. Technically, he's absolutely fantastic but he's still short on fitness and that's understandable.
"I didn't think that I'd be able to throw him straight in, and, with the loan only being for four weeks, we had to decide to leave it."
O'Hara has made just two appearances for Wolves this season after being frozen out at Molineux.