"There's no doubt about it, he could do the job standing on his head. No problem," Lambert told reporters.
"I've always said he's a fantastic manager and it would be up to him whether he'd want to go into international football or go back to club football. I don't know but whoever takes him has got a great manager."
O'Neill is hotly tipped to take over the managerial post and it has been rumoured that he could be approached within the next 48 hours.