I used to love watching him play - he was one of the best footballers in the world in his prime, a guy who just had absolutely everything - but his managerial career to date hasn't been great.
He set such standards on the pitch that maybe his expectations are hard for his players to live up to, a bit like it was with Paolo di Canio at Sunderland. If Roy has any intention of getting back into club management, then the Celtic post is an unbelievable one for him.
I can't believe he has anything to deliberate over. He should bite their hand off if they want him. While his record at Sunderland - he won them the Championship, then kept them up before abruptly leaving the following season - looks OK on paper, by all accounts things weren't great within the club. His record at Ipswich, where he was sacked after they dropped to near the bottom of the Championship, speaks for itself.
If he is looking for a route back, the chance to come to a club of the size of Celtic should be a no-brainer. But then, whether as a player, or in his managerial style, Roy has done things in his own way for a while.
To me, Roy hasn't proved beyond doubt his abilities as a manager. Sure, he has all the other attributes for the Parkhead job - profile, a Celtic man who has played for the club - but you can't say there aren't still question marks there.
Roy is definitely in the Neil Lennon mould, I don't think we should forget that, but if he is to be a success he is going to have to learn on the job the way Neil did.
At first, Neil was always intense with his players, but you can't do the same things all the time if they don't respond. Who knows, maybe Roy has already learned that after the problems at Sunderland and Ipswich.
But the bottom line is this: how hard is it to win the league with Celtic? There is undoubtedly success there to be had. Everything is there for Roy at Parkhead. What an opportunity it is to enhance his reputation, get people realising that he IS a good manager. It is an opportunity to send his managerial stock soaring again because I don't care what anyone says, it is pretty low right now.
Peter Lawwell is a likeable man and an efficient chief executive, so the only problem might be if Roy becomes overly demanding, or the way he puts things across.
He has never been the best at maintaining relationships - if you cross him, he just tends to leave - and it might be difficult if the chief executive had to go to him and say maybe this or that should happen.
But this Celtic team only lost three domestic matches last season, one in the league, one in the League Cup, one in the Scottish Cup, so I don't think he will need to rule by fear. There will still be challenges - things are never straightforward, there are always obstacles to confront - but you can't tell me Celtic won't be a winning side next season, and that might make it easier for Roy to relax a little bit.
That is why it is the perfect club at the perfect time for him. He shouldn't have to show his difficult side too much. I have never met Roy in person, but I suspect that five-month swansong he had at Celtic must have been a bit of a disappointment given the standards he sets.
Sir Alex Ferguson was critical of Roy in his autobiography - he accused him of bullying team-mates at Manchester United, and said as a manager he "needs money" - and when somebody like that comes out and says that you have to take notice.
Roy fired right back, but the challenge for him at Celtic would be learning when to take a step back, not going in with the iron fist all the time, better maybe to show his softer side from time to time in the day-to-day handling of his players.
I think the job could be perfect for Roy and believe he would make a success of it. But then again I think pretty much anybody would. You would have to mishandle it so badly for it to go wrong.
ONE thing appointing Roy Keane would do is increase the wider media profile of both Celtic and the SPFL Premiership and obviously that would be no bad thing.
For any top league to lose three of their biggest clubs - in this case Hibernian, Rangers and Hearts - can't be great. It will be a three-team shoot-out for the Championship title, but these are three teams with problems.
Hearts are in a transitional period and have a rookie manager in Robbie Neilson. Hibs are in utter turmoil, and with Rangers it is story after story.
One, or maybe two, of the three will be left disappointed. It will be some season.