I truly believes he thinks he should have landed that job. When Sir Alex Ferguson was the manager at Old Trafford, you went there as a humble visitor. As an opposition manager, you were visiting Sir Alex in his castle, but that is all up for grabs now.
I think Mourinho will enjoy this tonight because he will be able to get away with things he wouldn't have if Fergie was there.
It is an important game for David Moyes. He must stamp his authority on the touchline if you like, saying "I'm the manager of the biggest club in England."
We were reminded yesterday when Cardiff beat Manchester City how tough a league this is.
Mourinho has realised there is no need to come back to the Premier League and be nice to everybody. He is a competitor, and this is almost war for him. He is back to what we expected.
He has been pretty quick to slip into the "whatever it takes" mentality. He is making sure everybody knows he is back. It is fascinating to have him in England again.
Mourinho knows how tough it is when you think of Manchester City in Cardiff yesterday. City boss Manuel Pellegrini will wake up this morning realising just how difficult it is to win away games in this league.
Unlike in Spain, every game is full on. You can have the best squad, but it takes more than that. In Spain, you get a lot of four- or five-goal wins for the big two.
United v Chelsea is the first big match of the season, and I have a feeling United might just edge it.
It would be a brave call by Moyes to play Wayne Rooney this evening, and whatever he does regarding Rooney will be a big call.
We shouldn't be surprised about Mourinho's comments regarding Rooney being second choice. If you take what Moyes says at face value, then Mourinho is probably correct.
But as we know, you should never take statements like that as fact. Sometimes managers say things that don't come across quite right.
I think Moyes just expressed the belief that he was never going to be first-choice striker as long as Robin van Persie is there.
But there are plenty of other positions in the team that Rooney can operate in. I said three months ago that United would probably feel this is the right time to sell Rooney. I still have the instinct they will sell if they can find a suitable replacement.
If Fergie had still been there, Rooney would have been gone by now. It was easier for Fergie to sell Rooney than it has been for Moyes.
Obviously, Moyes coming in as new manager and selling Rooney as his first act in the job might not have been the wisest move.
People would have interpreted problems. Fergie has so much credit with the fans that he would been backed if he had sold Rooney. Having said all that, I still think Rooney might go. There is a reason why this story hasn't gone away.
That is because Chelsea continue to receive encouragement from somewhere. I believe Arsenal also want Rooney, but Chelsea are favourites in the race to sign the player.
That encouragement might well be coming from Rooney's camp otherwise somebody would have come out and ended it. And Rooney's agents are in a position to do that.
United can say they don't want to sell him, but Chelsea are going to bid again and I think Arsenal will want him.
There is no doubt Chelsea and Arsenal need that type of player, that aggressive type of British player that would enhance their squads.
United might be able to minimise the loss of Rooney if they find a replacement for him.
On the other hand, I think Chelsea are going after attacking players when they are still short of defensive-minded players.
You don't know if John Terry will play every game, and I don't think Mourinho would sleep well at night if David Luiz was his central defender this season.
A lot of people are saying Moyes's mindset is not to let Chelsea win tonight.
But the United players are used to winning at Old Trafford, and I think United at home will look to make a statement.
Chelsea will come to play which will suit United. United are not one of these teams that needs to control the game by having loads of possession. They will be content enough for Chelsea to come at them.
That back four knows it can defend, and they know they have quality on the break. I have a feeling United might just pip it, but it should be a great watch.