That Cristiano Ronaldo to Manchester United transfer rumours are back again, with the English Premier League club reportedly working on bringing the superstar forward back to Old Trafford from Real Madrid in this summer transfer window.

Ronaldo has been tipped for a move away from Real Madrid after already falling out with Rafa Benitez, who reportedly hasn't exactly filled the prolific forward with confidence.

The former Manchester United star was seen complaining about Benitez's training drills, one of which was a crossbar challenge.

Clearly not amused by that one, Ronaldo was quoted by AS as saying: "The ball is meant to be in the net. Not this sh**."

Benitez also surprised many by refusing to categorise Ronaldo as the best player in the world, when asked that question. Instead, the former Napoli, Inter Milan, Liverpool and Valencia manager clubbed Ronaldo with Gareth Bale, Karim Benzema and James Rodriguez.

"He is one of the best in the world," Benitez said. "It's difficult to pick the best. I think Cristiano, Bale, Benzema or James Rodriguez are all there, and then everyone has the player they think is slightly above the rest."

Benitez is under pressure to get Bale back into the Real Madrid centre-of-attention fold this season, considering how big a favourite the Welshman is of the president Florentino Perez, which is another reason behind Ronaldo's apparent discontent.

Clearly having been given time to ponder over his answer for "who the best player in the world" is though, Benitez did alter those comments ahead of Real Madrid's preseason friendly against Manchester City.

"When you work with Ronaldo you realise how competitive he is," the Spaniard added. "And that is why he is the best player in the world."

Considering all the issues that are reportedly in place in the Real Madrid training camp in Australia at the moment, the Manchester Evening News believes Manchester United are ready to take advantage.

The report suggests Manchester United want Ronaldo to be their marquee signing of the summer, and are confident of pulling off what would be a club record deal for the Portuguese.

While there might or might not be problems within the Real Madrid setup at the moment, getting Perez to sell Ronaldo to any club will take some serious powers of convincing.

Ronaldo is without a shadow of a doubt Real Madrid's best goalscorer, and even if Perez might be a big fan of Bale, replacing the Portuguese, if sold, will be next to impossible.

Such rumblings were on within the Barcelona camp last summer, with reports suggesting Lionel Messi was looking for a move away. But once the dust settled, Barca went on to complete the treble.

Let's just say there chances of Real Madrid pulling off a treble next season are slightly higher than Ronaldo leaving the Bernabeu, even to his beloved Manchester United.

But then, transfer windows are a window to strange happenings.