The player's work-rate was called into question by Sir Alex Ferguson in his newly published autobiography, but his successor insists there are no issues regarding the striker
The former Man Utd boss opened up about a number of topics in 'Alex Ferguson: My Autobiography', including describing Rooney as "not the quickest learner".
But Moyes has dismissed any present concerns regarding the England international's fitness, underlining his determination to succeed at Old Trafford.
"Wayne is completely focused on his football. He has been since the first day back in pre-season," Moyes told reporters.
"He's in good form - he's looking after himself and playing well."
Ferguson has also elaborated on the infamous United departures of David Beckham and Roy Keane in his memoirs and Moyes has welcomed the book and any further revelations it may bring.
Moyes added: "Alex Ferguson can do what he wishes. He's his own man. Certainly everyone at Old Trafford would love to hear what he has to say - the supporters certainly would.
"He has great knowledge and I am sure a lot of people will enjoy reading [the book].
"I am sure I will [read it] when the time arises - I have not got much time in this job, that's for sure."