Manchester United are Premier League title favourites says Manchester City manager Roberto Mancini

Manchester City manager Roberto Mancini (GETTY IMAGES)

Manchester City manager Roberto Mancini is certain Robin van Persie will improve Manchester United and has once again stated his belief the Red Devils should be seen as the favourites for this season's Barclays Premier League title.

It was confirmed this morning that Van Persie's move from Arsenal to United was complete, with the Dutchman putting pen-to-paper on a four-year deal at Old Trafford.

The capture of last term's Golden Boot winner represents a bold statement of intent on the part of United manager Sir Alex Ferguson, who is on a mission in 2012-13 to reclaim the Premier League crown his side were pipped to in dramatic fashion by their derby rivals City in May.

A week ago Mancini had already labelled Ferguson's men as favourites to win the title, and speaking today at a press conference to preview City's league campaign opening home clash with Southampton on Sunday, he made it clear his feeling on the matter had only grown stronger.

Asked if it was even more so the case that United should have the favourites tag with Van Persie among their ranks, Mancini said: "Yes, for sure, and I was serious when I said this last week because United have played for the title always, every year for 20 years.

"Although we won the last championship, we can't change this in one year.

"For this reason, I think they are favourites for the title, and now they have Van Persie - he is a really top player, the best striker last year.

"With Wayne Rooney, they will have one of the best couple of strikers in the Premier League."

Questions have been raised over the reported £24million fee for Van Persie, who is 29 and has suffered with injury problems in the past, but Mancini is in no doubt that United are better off for having the Holland striker.

He said: "I think Van Persie is one of the best strikers in the world. I am sure they are better with him. Anybody who bought him would be better."

It was felt Mancini wanted to sign Van Persie himself, although he claims it was not a realistic possibility.

"I felt he was going to stay at Arsenal or sign for another team, but not us," he said.

"We already have four strikers. It was impossible for us to sign another one."

The one player City have recruited this summer is England international Jack Rodwell, who could be set for his debut in Sunday's game, a week after his transfer from Everton was announced.

Last Friday Mancini had said he was "not happy" that his efforts to strengthen his squad up to that point had been frustrated, adding: "You have to speak to our sporting director (Brian Marwood), not me."

But after Rodwell's official unveiling this morning, the Italian insisted he had no problem with Marwood and expressed his optimism that City would do further business before the end of the transfer window.

"What I said last time was not because I had a problem with Brian - I don't," Mancini said.

"But when you are a manager, you want maybe sometimes to buy a player quickly. At the same time I know it is difficult because the market is difficult.

"It was important to start with one (signing) and now it is important to think about the game on Sunday.

"Then we have about 10 days until the end of the market and I think we will do (more business) - I am sure."

Rodwell, who Mancini regards primarily as a midfield option but also as a possible one in central defence, is joining an already star-studded squad and says he is ready for the potential battle he faces to hold down a place in the team.

"It is going to be a challenge and I am up for that challenge," Rodwell said.

"There are great players here and I want to learn from them and improve my game."

The 21-year-old has struggled with hamstring problems in recent times but says he is fit, with Mancini set to run the rule over him in training before deciding the extent of his potential involvement against the Saints.

Rodwell said: "Physically I am good. I had a couple of injuries last season, but that is all in the past now and I've had a good pre-season, so I'm raring to go."

Mancini will also assess the fitness of goalkeeper Joe Hart, who could return after missing last Sunday's 3-2 Community Shield victory over Chelsea due to a back complaint, while defender Micah Richards (ankle) and midfielder Gareth Barry (abdominal problem) are definitely ruled out.

Meanwhile, City have today confirmed Ferran Soriano as their new chief executive.

PA