Rooney scored his 20th goal of the season and reached another personal landmark when reaching a century of goals in Sunday evening's 3-1 victory over Arsenal.
The striker has been linked with a possible move to Barcelona and Real Madrid but Ferguson is adamant Rooney will continue to make history at Old Trafford.
"Rooney was unbelievable. He was the key player and they couldn't handle him,'' Ferguson told Sky Sports. "He's very happy at the club. He's popular among the players and couldn't be a better lad. He's down to earth and won't change because that's who he is.
"That's refreshing in this day and age of celebrity-type footballers with lots of money, but he never changes when some people do change with success.''
Regarding Rooney's contract situation, Ferguson said: "I'm sure that [United chief executive] David Gill is working with [Rooney's agent] Paul Stretford. Hopefully something does happen.
"That was a great performance by us. I'm very pleased. It's at this time of year that you need to kick on. Wednesday's performance galvanised us again and the players showed today they're sharp. We made lots of chances.
"The run-in is always a difficult period. We've handled it in the past and I trust the players to handle it again. We need Chelsea to drop points but Arsenal aren't out of it yet. I hope Arsenal go to Stamford Bridge and batter them next Sunday.''
Meanwhile, Nani reflected on his best game for for the club. The Portugal winger helped open the scoring when his chip across goal was palmed into the net by Gunners keeper Manuel Almunia, before setting up Wayne Rooney for the second.
"I think that was my best game. I played well, scoring and getting an assist,'' Nani said. "It was a fantastic performance from the team and I was so happy to help. I'm working hard every day to be fit for the team.
"I want to help the team play well. I can feel the confidence of my team-mates, the fans and the manager. I'm so happy and want to continue this good form.''
Arsene Wenger offered no excuses for Arsenal's capitulation and admitted he must restore morale before Sunday's trip to Stamford Bridge.
"We made massive individual errors and this is a massive disappointment for us. But we have to stick together,'' Wenger said. "We were poor and that we can do much better than that. We are conscious that we didn't deliver the game that was expected from us.
"When you're completely off the mark it's impossible to win the game. We must prepare to come back stronger. It's our job not to feel sorry for ourselves. Chelsea is a good opportunity to show we are united and strong.''