Former Manchester United icon Roy Keane has fired a warning to his former club over their expectations regarding Cristiano Ronaldo.
The Portuguese attacked continued his successful start to his second stint with the club on Sunday against West Ham.
Ronaldo netted the equaliser for the Red Devils before Jesse Lingard took all three points in the 2-1 win for Ole Gunnar Solskjaer's side.
But the megastar cut a frustrated figure in midweek as the 10-men of United slipped to a shock 2-1 defeat against Young Boys in their Champions League opener.
And Keane has warned his former side that other players will have to step up alongside Ronaldo if the club are to be successful this year.
Speaking on Sky Sports in the build up to the West Ham win, Keane said: "You look during midweek, he struggled upfront without getting decent support or possession.
"Man United have to be careful because Ronaldo’s come to the club everyone thinks it’s just going to fall into place, the players still need to step up and do better than what they had in the one or two years but he’s still a world class player."
But despite those concerns, Keane conceded that we have already seen the difference that Ronaldo can make
"We seen the best of him against Newcastle when you are creating chances getting balls in the box, we seen the problem that would cause United when they were up against it when they went down to 10 men." he said.
"He hasn’t got the energy or the desire to be up there by himself but when you bring a top class player in anything in the box he’s the best in the world. He was on fire there was no surprise he produced last week."
United's loss in Europe means Solskjaer has now lost seven of his last 11 matches in the Champions League.
But Keane is adamant United will "bounce back" - despite a couple of disappointing performances in the Premier League recently to go along with their humbling in Switzerland.
"The signs haven’t been great the last few weeks away from home,’ he added.
"I think away from home against Southampton, they weren’t great and could have lost that.
"At Wolves, they did get the win, and their performance wasn’t great, so I wasn’t that shocked [with the loss to Young Boys].
"Everything is exaggerated at United. They beat Newcastle, and everything is great; they lose during the week, it’s a disaster.
"It’s still early in the season. They’ve got three or four new faces into the club; it takes time to bed in. They’ll be disappointed with the defeat but they’ll bounce back."
