But the 31-year-old has been a virtual ever-present since breaking back into the Villa side at the end of October and looks set to line up against former club Wigan on Saturday.
O'Neill has been impressed by Heskey's recent contribution and is hoping to retain his services for the foreseeable future.
O'Neill told the club's official website: "Emile has done very well indeed. There has been some paper talk about teams, but no-one at this stage has enquired directly about him to me, although that doesn't really mean anything these days now.
"But I've been very pleased with him. He's got a few goals to his name as well too and if that gets back to the point I'm always talking about - it gives you a bit of confidence.
"For the most part, all season I've been delighted with the team and that would include him."