Wayne Rooney gave an almost perfect performance for Manchester United against Manchester City and showed just why he, rather than Robin van Persie, is the one player you would always want in your team.
Van Persie has been a fantastic addition to the United team and he showed that again with his late winner at the Etihad, but his goals are really the icing on the cake.
In terms of which player United need most, though, I would say it is Rooney every time because he offers as much at right-back as he does at right- wing and as a centre-forward.
When you are sitting in the dressing-room and your best player is also the hardest worker, it lifts everybody and gives something extra to everybody else.
It is a strange situation with Rooney, though, because regardless of how good a player he is, he keeps on having to answer questions about his form, his contribution and other aspects of his game.
Maybe people just look at him from an England perspective and put his United performances to one side. At the World Cup, particularly in the game against Algeria, he could not have played worse than he did if he tried.
But I have never been one of those who believed that Rooney was on the wane or that he was no longer the most important player at Old Trafford.
If you offered me all of the top players in the Premier League, all of the top foreign imports, I would still put Rooney ahead of them.
When he is not playing well, his effort can never be questioned and that is why he always offers something to the team. But against City, he was magnificent in so many areas of his game. Not only did he score two goals to put United on their way to victory, but he was back at right-back making tackles, he was creating chances and his touch and technique were top drawer.
Rooney is so good, that he gives you nine out of 10 when he drops into midfield and nine out of 10 when he helps out at the back.
There are players in the Premier League with better technique than Rooney, who score more goals and who can match him for talent, but none of them provide the full package like Rooney.
In recent weeks, Alex Ferguson has made a few references to Wayne's "frame" and talked about the need for him to play more often.
He then played him against Cluj in the Champions League in midweek when all of United's other main players were rested. But it's all psychology with Rooney and you have to say that Ferguson's tactic worked on the basis of his performance against City.
When you have a player like Rooney, who thinks he can be the best, wants to be the best and goes all out to prove it, sometimes a manager has to keep him on his toes by leaving him out of one game or playing him in another.
That kind of management is designed to make the player even better and nobody knows Rooney better than Alex Ferguson.
There are many ways to handle players, but Ferguson appears to know exactly how to get the best out of Rooney because he has now scored four goals in two games.
Rooney also looks to have curbed his temperament and he has long since ended the doubts about his ability in the air.
So, while Van Persie is the man who is scoring all the goals and grabbing all the headlines, United would find it more difficult to put up with life without Rooney than their top scorer.
If you take all of Rooney's effort and desire out of the team, United would have problems because you just cannot find players who give you what he does. Van Persie's addition has made a difference, though, and it showed against City. When you look at the starting teams on Sunday, there were two players making their derby debuts.
One was Van Persie, the other was City defender Matija Nastastic and that says a lot about the current position of the two clubs.
United have grown stronger with the addition of a £22m striker, but City have not progressed and that is why United are now six points clear at the top of the league. (© Daily Telegraph, London)