The Nigerian striker joined on a free transfer last summer after leaving Sevilla but has struggled with injuries during his time at Celtic Park.
Now fully fit, the 29-year-old is rediscovering form at a vital point in the season. He made a big impact on Sunday, coming off the bench to score the winner in a 2-1 victory over Hibernian at Easter Road.
“That’s a conversation for another day. Right now, his fitness is the most important thing, and he has to keep proving that he’s fit on the field,” O’Neill told the media.
“What he’s done for us has been terrific, especially recently. The club will weigh up his overall contribution against his injuries over the whole season.
“Although he says he’s very young, time does catch up with players—though I think he’s only 29 or 30. If the club keeps him, he would benefit greatly from a proper three or four-week pre-season.”