The 35-year-old is currently facing a race against the time to recover from the injury he sustained while playing for LA Galaxy.
However, O'Neill has revealed that he could take national team captain Keane to France in a coaching capacity if the striker fails to prove his fitness.
"I think Robbie would be thinking he'd want to make the final 23 first and foremost," said O'Neill, when asked about the possibility of taking Keane as a part of the coaching team.
"We'll see how things develop after that, but he has been very influential in the group. He's been very supportive while he's been here.
"Even when he hasn't started, he's still with the team, so that is a thought, I must admit."