By Phil McNulty BBC Sport Online chief football writer

Roy Keane's hell has finally frozen over - even his long-time apologist Sir Alex Ferguson was aiming potshots at Old Trafford's tormented talisman.

Manchester United boss Ferguson has always been Keane's shield against reality as his list of footballing offences to be taken into consideration grew.

If Keane was having another of his darkest hours, he could always rely on Ferguson to let a glimmer of light into his tortured world.

Ferguson initially mounted a defence for Keane clattering an "innocuous" elbow into the head of Sunderland's Jason McAteer, an offence that led to his red card at The Stadium of Light.

But even the man who has almost become Keane's personal George Carman QC was powerless in the face of the grim evidence of his captain's stupidity.

Ferguson fell back on the tried and trusted complaint about television camera angles blurring his initial verdict - although every one on offer merely confirmed Keane's guilt.

Give Ferguson credit for his U-turn, probably made easier by his hatred of the use of the elbow.

And it marked a watershed in the public relationship between Ferguson and Keane, namely the first time he has delivered such a public rebuke to the man who is his eyes, ears and voice on the pitch.

The relationship between Keane and Ferguson has been one of the most enduring and fascinating aspects of the Manchester United empire built by the brilliant Scottish manager.

As with Eric Cantona, Ferguson has accepted there is a price to pay for football greatness and it is a deal he has willingly bought into with Keane.

Ferguson gave Cantona a footballing freedom and a licence to be himself, keeping faith with him throughout all the sorry episodes that marred his Manchester United career.

In return he was rewarded by the touch of Gallic genius that was the catalyst for United's years of domination.

He has handled Keane in similar fashion, dealing with his misdemeanours by always extending support, in public at least.

Ferguson finally criticised Keane

But it may be that Ferguson's constant indulgence of captain Keane has created a monster that even he is now struggling to control.

Even on Saturday, when Keane had been suckered into a red card by Jason McAteer - hardly the sharpest knife in the drawer when it comes to the game's black arts - Ferguson's first instinct was a defensive one.

Keane now acts as if immune to the basic rules of his chosen profession, acting in a way that shows little regard for the image of Manchester United.

He is now almost bigger news than Manchester United itself, and we know Ferguson can't have that.

We can only speculate on the nature of their relationship, but the most obvious theory is that Ferguson sees so much of himself in the fiercely driven firebrand, that he now shares an automatic empathy with Keane.

But the signs are that Keane's football career is lurching out of control - and Ferguson was finally left with no option other than to do the deed that dare not speak its name inside Old Trafford.

And that is criticise Keane before the watching Premiership public.

Even Ferguson cannot deny the evidence of his own eyes, and the sight of Keane shoving Phil Neville, snarling at the journeyman McAteer, then finally getting a red card was ugly in the extreme.

Keane's enforced absence may not only allow him to sit out an FA ban and spend some time out of the limelight.

It may allow Ferguson to question whether sparing the rod has spoiled the child - and for a man who has treated Keane like his own son, that would be a massive admission to make.