Speculation over Rooney's future rumbled on for most of the close-season, despite Moyes insisting that the England forward was not for sale.
Moyes is adamant that he had no doubt Rooney would return from injury and start scoring for club and country, praising his mature, responsible attitude to the game.
He told reporters at today's pre-match press conference: "He's at the age in his career where he would be one of the main players and he's certainly a main player for Manchester United.
"He takes responsibility, scores the goals that are required and he's done that from a young age. The age he is now, he's got that maturity and it shows in how he plays and the condition he is in with the way he is playing for club and country.
"I saw him like this on the first day of pre-season yet I had to keep telling everyone that was the case because the media thought it was different. You can see by his form and the goals he is scoring that what I was saying was right."
The 27-year-old has scored five goals in his last six games for United, as well a pair of strikes against Poland and Montenegro to help England secure World Cup qualification.