The Premier League champions welcome local rivals Manchester City to Old Trafford at the weekend and the former United forward backed the England striker to give a typically fiery performance on derby day.
McClair believes that Rooney has improved since last year, and is now up there with the current greats of the game such as Lionel Messi, Kaka and Cristiano Ronaldo.
"You would have to look at him on the same level as them," the Scot told The Manchester Evening News.
"Wayne Rooney has been a great player for a long period of time and year in, year out he has got better and better."
"He's proved how important he is for England, but I'm a Scot – I don't care what he does for them. He's been a very important player for United for a long time. He's done very well since he came here from Everton and irrespective of what he is asked to do he's done well.
"He wants to be a goal scorer and the main striker. He will be given that chance this season and I am sure he will score lots of goals."
McClair added that the recent seismic changes at Eastlands have been noted at Old Trafford.
"Anything that happens in football gets registered everywhere. The £80m transfer of Ronaldo to Real Madrid was worldwide news.
"Football is the most popular sport in the world and there's so much opinion. You would be following the situation where there is a club in Manchester who, in the last transfer window, tried to sign one of the best players in the world in Kaka, on top of the previous signing of Robinho.
"There is always interest and talk about it, but we are more interested in what United are doing. When I was first here, City finished above us. There has always been rivalry. City have had various degrees of success and at one point dropped down to the third division before coming back up," McClair added.
"We are in the situation now where they are looking to build a club from the top. When you are spending that type of money you are looking to build a squad that is capable of challenging the supposed top teams in England and Europe. That's their main goal.
"We will see what happens when it comes down to the fight for trophies at the end of the season."
Zack Wilson, Goal.com