By Phil McNulty
Chief football writer
Roy Keane is poised to take the massive step that has proved too much for so many great players before him - the move from the pitch to the dug-out.
Roy Keane will aim to emulate Sir Alex Ferguson
The most committed winner in Premiership history is on the brink of being appointed boss at Sunderland, a Championship team and a club that has forgotten how to win.
Chairman, and current manager, Niall Quinn reacted to the Carling Cup defeat at Bury by announcing he was close to appointing "a world-class manager" - and it appears that man is actually someone who has never managed at any level.
Throw in Keane's confrontational and combustible personality, and you have a strategy from Quinn and his former Republic of Ireland team-mate that is high-risk in the extreme.
Just take his departure from the World Cup in 2002 after an infamous ruck with Mick McCarthy.
He may have to bite his tongue and count to 10 now he is a manager. He will have to demonstrate sympathy and understanding.
Can he achieve it? Will he be able to oversee a group of players who cannot dream of having a talent and drive to match his?
Keane is hardly renowned for his patience with under-achievers, and he will find plenty of them waiting to greet him if he finally settles behind a desk at the Stadium of Light.
And a career liberally sprinkled with honours is no guarantee of managerial success. Keane's attempt to make the transition will be intriguing - and potentially hazardous in a lower division environment that is alien to everything he has experienced in his previous life at Manchester United and Celtic.
This is the downside and will not figure in the considerations of Sunderland chief Quinn and a hugely loyal fan base that have gone from craving success to craving for a single win.
Quinn appears to have pulled off a massive coup, and make no mistake Keane has had the best managerial education available under his mentor Sir Alex Ferguson.
He has long been regarded as the on-field embodiment of the fire, desire, and will-to-win of his brilliantly successful and single-minded manager at Old Trafford. His master's voice on the field.
If he can inject a fraction of that into Sunderland, he will prove an inspired appointment, but expect a rocky ride.
His former Republic of Ireland boss Brian Kerr has no doubts.
He told BBC Sport in 2006: "I could certainly see him as a coach and as a manager - he is very intense about the game and thinks a lot about it.
"He loves the competitive nature of the game and he likes the idea of winning matches.
"He understands the key to winning matches is in the preparation. He has talked about how important it is in the way you prepare for games - that gives him a great start.
"To be a manager you have to give time, energy and dedication to the job. He has the strength of personality, communication and intelligence to go into it if he wants to do it."
Keane will have no trouble keeping his distance and establishing respect from Sunderland's players. He was not even regarded as close to many of his team-mates at Manchester United.
He once famously said: "I'm not at Manchester United to be liked" - just as well given his capacity to deliver the harshest of messages to colleagues he felt dropped below the standards he did not simply expect, but demand.
Keane will have to quickly learn that all players are not as outstanding or as driven as himself, especially those who have struggled so desperately for the last 12 months.
Even so, expect fireworks and quickly.
If anyone has been enjoying an easy life at Sunderland, the party is over. If anyone wants a quiet life, they are in the wrong place.
But, more importantly, if Sunderland's fans were looking for a saviour they may just have found one.
Quinn suggested he would appoint a manager who would prove his new Sunderland regime meant business.
Keane is certainly that man - but the outcome of this bold appointment is no foregone conclusion.
If he can light a spark under a huge club, he will achieve legendary status. If the job does not match Keane's expectations, or if he sees something that does not meet his standards, will the toys fly out of the pram?
This is why the predicted appointment of the hugely-respected and shrewd Brian Kidd as his right-hand man will be a wise move.
One thing is for sure, once Keane walks into the Stadium of Light, life will never be the same again for Sunderland.