Cristiano Ronaldo
Cristiano Ronaldo backs Manchester United to win the title under Louis van Gaal.Getty

Real Madrid star Cristiano Ronaldo has backed Louis van Gaal to win the Premier League title with Manchester United.

Sir Alex Ferguson retired after helping the Red Devils win their 20th league title in May 2013. David Moyes succeeded the great elder at Old Trafford and under the guidance of the former Everton manager, United struggled last season as they finished seventh in the league table.

Moyes was shown the door just 10 months into his six-year contract and he was replaced by Van Gaal earlier in the summer.

United are still to hit top form and with only the Premier League to concentrate, their priority would be to finish in the top four and return to the Champions League next campaign.

Ronaldo has urged his former club and their fans give Van Gaal time to bring success to Old Trafford. The Portuguese international remains confident that United will be champions again "very soon".

"Van Gaal is a fantastic coach and I am certain he will make United champions again – if not this year then very soon after that," Ronaldo said, as quoted by the Mirror.

"Sir Alex Ferguson said that Van Gaal will need time - and he is right. Because, in the beginning at United, even Sir Alex didn't win anything for a few years. To get a good squad and a good team takes time, so let's give Van Gaal the time he needs."

United will take on Chelsea in the Premier League clash at Old Trafford on Sunday. The Blues are topping the table and Ronaldo says Jose Mourinho's side can go on to win the title this season.

"Chelsea are stronger than all the other teams this year although in the Premier League you never know what can happen," the Real star said.

"Chelsea have made a great start and they can be champions. I hope Manchester United can come again at the top of the league but, at the moment, they are many points behind Chelsea."

"The Premier League is complicated. Even the clubs at the bottom of the table can beat those at the top, so it is very tough," Ronaldo concluded.