STAN Collymore, who played under O’Neill at Leicester, is among those who believe the Northern Irishman had missed having Robertson at his side.
He told talkSPORT: “Martin O’Neill is a dictatorial manager in the style of a Sir Alex Ferguson or a David Moyes – in other words he deals with everything.
“He knows the cost of everything, he wants total control of everything.
“John Robertson was the conduit between player and manager. When I was at Leicester I would go out and do the training with Steve Walford and everything would be quite jovial.
“John Robertson would watch training, perhaps go in a couple of times to see the manager who probably wouldn’t even come out until the last 10, 15 minutes of the session where everything got much livelier because it was unusual for the gaffer to come out and oversee training – like Sir Alex Ferguson or like David Moyes - and what John Robertson would do would be to report back.
“Who’s looking sharp, who’s not looking so sharp and I think in terms of this season Martin O’Neill just hasn’t looked himself.
“He hasn’t had that sounding board with John Robertson, Robbo decided not to make the trek up north and from what I understand JR almost had enough of the modern-day footballer.
“I think that has had a massive impact.”
Collymore was blasted by O’Neill last year after the commentator was among those rumouring O’Neill may quit