Rooney is still looking for his first goal since March after failing to find the net in either of his two 45-minute pre-season appearances for Manchester United, or the hour he featured for England in their 2-1 win over Hungary in midweek.
It has been a frustrating period, which started with the ankle injury that forced him to miss what turned out to be the Premier League title decider against Chelsea, and the World Cup when, like so many top strikers, Rooney failed to make any impression.
Capello remains convinced of the 24-year-old's talents, and has no fears about the contribution he will make to England's Euro 2012 qualifying campaign. However, for those hoping Rooney will make an explosive start to the season, the England coach has some words of caution.
"I expect Wayne Rooney to have a good season but he needs to play,'' said Capello. "I studied him, along with a number of other players, for three years when I was a club manager, working out how long you needed to find normal form.
"It was 500-600 minutes minimum. At the moment he has played 150. For this reason. I think he needs to play a minimum of three more games to find his correct level.''
Rooney applauded all four sides of Wembley when he was substituted in midweek. It was interpreted by some as a sarcastic reaction to the booing he had been receiving which, given his controversial comments immediately after England's failure to beat Algeria in South Africa, have led to people wondering if he was about to quit the international scene altogether.
"No. I spoke with him. He is OK,'' stressed Capello. "I don't think Wayne Rooney would consider quitting England. He is a really good boy. He likes to stay with us. He won't be badly affected by what happened at the World Cup. We know it is possible that he wouldn't play well. But he has to forget. It is part of the job. You have to move forward.
"The reaction of the fans was normal. They want to see the best Rooney and the best team. Everything is best, best, best. But it is not possible all the time. You have to wait for him.''
Rooney played the first-half up front on his own before Bobby Zamora was introduced as his partner at half-time. Both moves worked to some extent, even if Capello's view is that Rooney's form is the key to how well each tactic fits together.
"He can play on his own or with someone else,'' said Capello. "The thing is, when you are in good form you can do anything. If you are not you can't play with anyone.''