The two strikers combined during United’s
He added: “I think Rooney will explode again soon. It’s just the start of the season. I think Rooney will start scoring soon, once he gets a few games back. We know that, his track record tells you that each year he gets better with his finishing.
“Van Persie, in his maturity, 29 years of age, the season he had last year has brought maturity to him, I think. And he has had a great start, seven goals.
"If I get him and Wayne and possibly one of the other strikers, (Danny) Welbeck or Chicharito, get to around 20, we are in business.
“Because I think the other two will get 20. I think Rooney and Van Persie will get over 20.”
The likelihood is that Rooney will again play in behind Van Persie at St James’ Park although that would possibly mean in-form Shinji Kagawa again missing out with Ferguson admitting that his attacking options are making it increasingly difficult for him to select his side. “I think I know my team, but it’s difficult,” he acknowledged.
The return of Rooney, after the gash he sustained during the victory against Fulham in August, has added to those options with Ferguson dismissing concerns over the striker’s fitness and also suggestions that Van Persie is his replacement.
“Rooney is fit, he has trained really well,” the manager said. “The period he was injured, I think that was key to it. He maintained his fitness which is important because he’s a stocky lad.
"He is very stocky, he is going to have to train well all the time. There is no doubt about that. Some players like Ryan Giggs are blessed but they’re not all going to be like Ryan Giggs, are they?”
Van Persie’s arrival, for £24 million from Arsenal in the summer, has helped “take the load” of Rooney with Ferguson revealing that the Dutch international has been working after training “with the sports science people” to improve his own fitness. “I don’t think about Van Persie settling in,” he said.
“What I know is in his first games he was short of fitness and sharpness. His training sessions are getting better all the time. He’s doing a lot of work after training. He asked for it because he knows he has make-up time because he missed pre-season training. He’s a good pro actually, looks after himself.”
Despite Ferguson’s optimism, United go to Newcastle having lost two of their opening six league matches – including last week’s home defeat to Tottenham Hotspur ending the visitors 23-year barren spell at Old Trafford.
United certainly need to be wary against Newcastle – who are returning to form, having beaten Bordeaux 3-0 in the Europa League in midweek with Papiss Cissé scoring.
United also lost the corresponding fixture 3-0 last season and cannot afford another defeat so early in the campaign.
But Newcastle manager Alan Pardew is very alive to the threat a fit and in form Rooney will pose his side. “He’s a fantastic player, one of my favourite players,” Pardew said.
“I love him in terms of his passion for the game and the way he plays it. He is England’s best player and changes the game for Manchester United.
"He changes them from a top four team to a top two team, that is how powerful he is.”
Meanwhile England manager Roy Hodgson has also praised Rooney, claiming there is a tendency to put the 26 year-old under “an enormous amount of pressure” because of his “exceptional ability” which leads to everyone believing he can “be some sort of messiah”.
However Hodgson said he was “really excited” to have Rooney available for the forthcoming World Cup qualifications ties against San Marino and Poland and said he detected the striker was “fit and enthusiastic”.
But he stressed there was also a need for caution. “The moment he doesn’t play like a genius we want to write him off as being hopeless. That is very unfair,” Hodgson said.
“A younger player gets more leeway. Every time Wayne Rooney goes on the field people expect him to be magnificent. We all know he is a magnificent player but football doesn’t give you the opportunity to be magnificent every time you step onto a football field.
“I’m looking forward very much to the next couple of years with Wayne, he’s going to be an important person as each team needs that person up front who can make a difference, who scores the goals or sets them up. He made a big difference against Spurs and Cluj.”