Roy Keane has alluded to losing respect for Alex Ferguson because he felt he was 'thrown under the bus' when he was turfed out of Old Trafford.
The Man United icon reflected on his infamous 2005 exit from the club in an in-depth sit-down with Jamie Carragher.
He said: "Sometimes he'd back you, he'd fight your corner about a contract situation but ultimately I kind of lost that respect at the end when I felt he threw me under the bus.
"I'd like to think I was low maintenance. I thought I was.
"But come the end when I thought managers were really disrespecting me and throwing me under the bus - that's when I went 'no, no, no'.
"So I've never lost a wink of sleep over that Jamie, I haven't honestly.
"We all do stuff, but when I look back I don’t think I did anything wrong. But it takes two to tango.”
He also touched on the other major falling out of his career with Mick McCarthy before the 2002 World Cup.
He added: "But all in my playing time there you had to go and try your best.
“Then again, aren’t you supposed to do that? I had that with Ireland and Mick McCarthy, but I never went out on the pitch and didn't give my best. You have to.
“I was let down, nothing will change my mind on that. You hear about players falling out with players every week, but that wasn’t me."
The Corkman has previously stated Brian Clough was the best manager he ever played for rather than the Scot with whom he dominated English football.
In one of his autobiographies he cited Clough being a warmer character which tallies with these most recent quotes as the harsh reality of being an ageing player caught up on Keane and Ferguson was ruthless enough to no longer view him as indispensable.
He wrote: "I worked under two great managers and I put Brian Clough ahead of Alex Ferguson for a simple reason.
"What was the most important thing in my football career? Brian Clough signing me. That kick started everything.
"Different managers, both brilliant. I think Clough's warmth was genuine. I think with Sir Alex Ferguson it was pure business – everything is business. If he was being nice I would think: 'This is business, this'.
"He was driven and ruthless. That lack of warmth was his strength. United was a much bigger club than Forest but his coldness made him successful."
As Keane acknowledged, that ruthless streak was a valuable trait in making the fiery Scot one of the all-time greats.
Over the course of his 26-year stint at Old Trafford he recognised when key figures had to be moved on in order to allow younger players to flourish as leaders.
This viewpoint was expressed just two weeks ago by longtime United strength coach Mick Clegg who cited Keane's departure as a long-term boon as the likes of Cristiano Ronaldo and Rio Ferdinand were able to step forward into the void in the dressing room and lead another great team under Fergie.
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