Man United have no chance without 'abnormal' Ronaldo, but Rangnick may be without him

But new interim boss Ralf Rangnick may be forced to begin his Old Trafford reign without the Portugal star - who is a major injury doubt for Crystal Palace.

There have been questions over whether the 36-year-old would suit Rangnick's famous, high-octane 'gegenpressing' philosophy.

Ronaldo was rested by caretaker manager Michael Carrick for the 1-1 draw against Chelsea amid questions over his work off the ball.

However, football's all-time record goalscorer reminded everyone of his enduring importance with his 800th and 801st career goals in the 3-2 victory over Arsenal on Thursday.

Rangnick heaped praise on Ronaldo at his first press conference on Friday, dismissing any suggestion their ideas do not match up.

The Sun reports that Ronaldo damaged his knee doing his trademark celebration against the Gunners, which means Rangnick may be forced to leave his star player out at Old Trafford on Sunday.

But former Republic of Ireland international Cascarino insists Ronaldo simply must play whenever fit if United have any chance of finishing in the top four.

"There is no bit of logic in my head that anybody would even conceive that Ronaldo isn't important to them this season," Cascarino said.

"It's already evident. For people to go, 'Oh, his age is 36, you've got to manage him'. Yes, within reason.

"This isn't a normal guy. This is a physical machine. He is unbelievable. He is way under his years in physical condition.

"You're going to have to use him for the here and now. The present, by the way, is really important in football.

"People want to talk about long-term solutions. Think about the present. That affects the long-term.

"United might not make the top four without him, they might make the top-four with him.

"He is capable of delivering for them to be a top-four team. Without him, they have got no chance of making the top four."