Few could have foreseen the 28-year-old playing such an important role for the Red Devils after a summer in which his future had looked in doubt.
However, after Chelsea's overtures were rebuffed, the England forward has knuckled down and on Saturday helped United to a 3-1 Premier League victory at Fulham - their fourth straight win in all competitions.
Rooney played a key part in the success at Craven Cottage, providing an assist, a goal and energy that allowed him to take hold of the match when the hosts threatened.
The striker appears to be blossoming under Moyes' tutelage - a far cry from their well-documented fractious relationship at Goodison Park.
"He is a big leader in the team and desperate for the team to be successful," the Scot said. "Obviously, having a successful team helps him as well.
"He has got leadership qualities. He is a man when he is on the pitch.
"On Saturday, we felt young Adnan (Januzaj) needed to drop in so I had to pull him out for the last 15 minutes to make sure we didn't do anything stupid.
"He understands that and I think he is at an age now where he sees that as well."
Rooney's assist and goal at Craven Cottage bookended a whirlwind 13 minutes in the first half.
Antonio Valencia opened the scoring from the forward's pull back, with Robin van Persie netting before Rooney struck - a ruthlessness often lacking at United this season.
"We have had spells like that but we haven't scored the goals," Moyes said.
"I can think of two or three games very similar, where we have had that sort of play but not got the goals at the end of it.
"I think it has been coming in a way, and thankfully on Saturday we got them quite early on."
United are now slowly but surely quietening the naysayers, having gone unbeaten since losing at home to West Brom on September 28.
Meanwhile, United Javier Hernandez sparked speculation over his future at the club on Sunday by apparently retweeting a link to a story in which he was encouraged to leave Old Trafford.
Hernandez's verified Twitter account, @CH14-, posted a link to a story on the Sky Sports website in which his fellow Mexican Carlos Vela said he should look to leave United if he does not start playing more regularly.
The 25-year-old striker came off the bench to score the winner in a 3-2 victory over Stoke a week ago but was an unused substitute for the win at Fulham.
Hernandez has been in and out of the United side since signing from Guadalajara in 2010 and this season has struggled to earn a start in the league ahead of Van Persie and Rooney.
In the article retweeted by Hernandez, Real Sociedad forward Vela said: "If he plays regularly he will score, so I don't totally understand why a player of his quality has not played more games.
"If he doesn't play regularly he will need to think about leaving."