The 27-year-old has scored in just one Premier League game this term, when he hit two goals in the 4-2 Old Trafford victory against Stoke in October, and has only one Champions League strike – a penalty against Braga – to his name this campaign.
A month-long absence with a gashed thigh and a recent bout of tonsillitis have restricted Rooney to 14 appearances in all competitions and Ferguson, who called on the player to work on his fitness during his recovery from the thigh injury, believes that the stop-start nature of his season has contributed to the England forward's diminishing returns in front of goal.
"That is what we're seeing," Ferguson said. "He is missing bits of games, and I think Wayne is the type of player who can't miss games. With the frame he's got and the type of person he is, he needs to play all the time."
Rooney's worst start came two seasons ago, when after the furore over a transfer request and having spent time at a boot camp in Portland, he went into December with just two goals, both penalties, against West Ham in the league and Rangers in the Champions League.
Despite Rooney's lack of goals this season, he is credited with providing six assists in the Premier League, mainly for 12-goal top scorer Robin van Persie, but Ferguson said he expects the England forward to score more than he provides.
"I'm happy with that part of his game (assists)," Ferguson said. "He can contribute to the team's success, fine, but we would rather he scored more.
"I think he is going through a period that all strikers go through. He is not scoring, but it will change once he starts to score regularly and it will become better for him."
The arrival of Van Persie, a £22m signing from Arsenal, has shifted the emphasis away from Rooney, with United's attacking play now focused on providing for the Dutchman, rather than Rooney, whose deeper role has contributed to his increased number of assists.
And Ferguson concedes that Van Persie's presence has led to an evolving approach within the team.
Ferguson said: "With Van Persie coming in, without doubt he is an up-front player, there is no question about that.
"I think the players are now starting to realise what a good player he is and hopefully that understanding gets better. I think there is more awareness about the runs he's making.
"There were some games where the way we kept possession was middle to wide, to middle and back to wide, without using the central area.
"But I think there is now more awareness about the runs he (Van Persie) is making and the awareness he has up front."
Ferguson's attacking options have been reduced, however, with the manager confirming that Portuguese winger Nani faces a further "four to five weeks" on the sidelines with a hamstring injury.
Shinji Kagawa, the Japanese attacking midfielder, continues to struggle to overcome the knee injury that has kept him out of action for over a month and he is not expected back in action until late December.
Captain Nemanja Vidic has returned to training following a September knee operation, however, and Ferguson is planning for the defender to face CFR Cluj in Wednesday's Champions League tie – four days before United face Manchester City at the Etihad Stadium.
"Vidic has started training, which is good news," Ferguson said. "For the last year and a half, he's only played about 10 or 12 games, but he's got experience and knows what's best for himself and when to go back in the team.
"He's not involved in the real competitive part of training, but at least he's back with the first team and it would be nice to play him on Wednesday in the European game.
"I wouldn't be afraid of playing him. He has done all his work, he's just short of match practice. I wouldn't be averse to playing him."
With Ferguson admitting that he is open to phone calls from emerging young managers seeking advice following a conversation with Reading's Brian McDermott, the Scot mischievously refused to rule out similar contact from Rafael Benitez should he require tips about how to handle his difficult start at Chelsea.
"Lots of younger coaches come here for a couple of days at a time and we've always been open to that kind of thing." Ferguson said. "It's no problem for me taking a phone call – it's only 15 minutes of your day."
And Benitez? "You never know!" Ferguson said. (© Daily Telegraph, London)
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