Whilst Moyes insisted referee Neil Swarbrick was right to merely show Rooney a yellow card for his kick at Cardiff's Jordon Mutch on Sunday, with plenty of former professionals insisting it should have been red, the Scot conceded the striker was "probably a little bit fortunate".
However, such has been Rooney's superb form this season, Moyes is reluctant to do anything that might jeopardise that, including tempering his combative style.
"He is an aggressive player," said Moyes.
"It is a big part of his game. He plays with his heart as well as the skills he has got in abundance.
"That is the way he is and that is the way he was when he was a boy at Everton with me.
"That is what a lot of people have said might have been missing from his game last season.
"It is certainly not missing now. He has the hunger and desire back. He is committed for everything.
"I would rather have a Wayne Rooney that way than any other way."
Moyes has been widely credited for Rooney's overall improvement in demeanour, which look increasingly likely to end with the 28-year-old signing a contract extension, that appeared inevitable at the end of last season.
His form has been brilliant too.
In addition to the incident with Mutch, he also scored one and made United's second in the 2-2 against Cardiff.
It is the reason why he is the most scrutinised English player of his generation.
"That is what happens with Wayne - a lot of attention," said Moyes.
"Everyone recognises the form he is in. He scored a goal again and made another.
"Maybe more attention has been drawn to something else rather than his goal or making another goal but the attention for all this season has been on his good form."
Rooney's discipline, in general, has been impressive in recent times.
He has not been sent off since the incident in Montenegro two years ago that led to him missing the first two matches of Euro 2012.
In United colours, Rooney has not been dismissed since March 2009, when he was red carded for two bookable offences at Fulham.
"Wayne Rooney's form and his attitude and his temperament have all been first class," said Moyes.
"I couldn't fault any of them.
"There will always be times when players have little bits when it doesn't always go. On that occasion, Wayne was probably a little bit fortunate.
"But the referee made the right decision.
"I want Wayne to have fire in his belly. He plays better when he is tough and aggressive.
"I don't want to change Wayne Rooney that's for sure.
"I don't want him to be kicking at anybody but I want him to keep being aggressive. I want him to keep challenging and running.
"At the moment we are seeing a really good Wayne Rooney who is in top form and scoring goals as well."