Published Monday, 09 December 2013
Roy Keane, who is now assistant to Republic of Ireland boss Martin O'Neill. (© Getty)
There has been no love lost between the two firebrand characters over the years, with Keane leaving Man Utd in 2005 'by mutual consent' - but largely over his outspoken views.
Speaking about Sir Alex in a new documentary for ITV4, focusing on his bitter rivalry with former Arsenal captain Patrick Vieira, Keane says that their relationship is now "non-existent".
While the retired manager is now a director at the Old Trafford club, the one-time driving force of his team claims he still doesn't want to let go of the reins.
Everything is about control and power. He's still striving for it now even though he's not manager. There's massive ego involved in that.
The former midfielder even takes issue with praise from Sir Alex in his autobiography, for "covering every blade of grass" in the 1999 Champions League semi-final second leg clash with Juventus.
"Stuff like that almost insults me. I get offended when people give quotes like that about me. It's like praising the postman for delivering letters," Keane says.
But he admits he was upset to leave the Red Devils, after the infamous interview he gave MUTV in which he heavily criticised his own teammates.
"I did shed a few tears in my car for about two minutes, but I also told myself I had to get on with my life," he says.
Keane cites Brian Clough, his former boss at Nottingham Forest, as the best manager he has worked with during his career.
The documentary Keane and Vieira: The Best of Enemies will air on Tuesday night.
© UTV News