Rooney pulled the strings in a disciplined performance in Wednesday's 2-0 Champions League win over Otelul Galati but if he is picked for Saturday's home Premier League match against Sunderland, he can expect to resume his normal duties.
"When you've got a player who I think has scored 10 goals so far, you want him to be in positions where he will get even more goals and I think that position is in his normal place," Ferguson told a news conference.
The England striker was playing out of position because of injuries to Tom Cleverley, Michael Carrick and Darren Fletcher and could well be called upon if they are ever short again.
"It's conditional in the sense of what midfield players I have available," Ferguson added. "We decided why not play Wayne there because he's got the appetite for it, he's got the energy levels for it.
"Last night his awareness of people around him was really really good. His first touch of the ball was excellent. I'm not putting any marker down for that position really because it depends what is available elsewhere."
Cleverley has been ruled out of Saturday's match against the 14th-placed visitors but Carrick is back in training and Fletcher is fit, meaning Rooney might have to return to being a striker despite his belief he can play anywhere on the pitch.
"He says his best position is centre-half but I'm not about to try that," Ferguson laughed.
FERGUSON'S FAIRYTALE
Captain Nemanja Vidic should return for second-placed United, who trail leaders Manchester City by five points, after sitting out the Galati game due to suspension.
Midfielder Anderson is doubtful after picking up a knock against the Romanians, while winger Ashley Young and defender Chris Smalling remain sidelined with foot injuries.
Striker Michael Owen, who limped off with a thigh injury after just 11 minutes on Wednesday, was having a scan and Ferguson did not know how long he would be out for.
The United boss will come up against familiar faces against Sunderland, with manager Steve Bruce, defender Wes Brown and midfielder Kieran Richardson having served him during the 25 years he is marking at the club this weekend. Sunderland's former United defender John O'Shea, however, will miss the match through injury.
Ferguson has kept talk of his Old Trafford quarter of a century low-key, putting the "fairytale" down to the quality of the players he has been lucky enough to be in charge of.
"It's been a really fantastic spell for me and something you don't think is going to happen," he said. "It's been a bit of a fairytale to last so long and I appreciate that.
"I'll continue as long as I feel healthy enough to do it," the 69-year-old added. "In management, things change as the years go on. It's different now even to seven or eight years ago. A lot of things have changed."
