Ferguson to limit Ronaldo appearances to avoid burn-out

Sir Alex Ferguson will give Cristiano Ronaldo the Ryan Giggs treatment to ensure he does not have his career shortened by burn-out.

After an inconsistent first few months at Manchester United, Ronaldo has hit top form over the last fortnight, in the FA Cup semi-final against Arsenal and coming off the bench at Birmingham on Saturday.

Prior to today's match against relegation-threatened Leicester at Old Trafford, Ferguson said: "Cristiano is a sensational talent, but we have to be careful and make sure we monitor the number of games we give him.

"Ensuring young players do not get burned out too early is one of the things I have learned in my time as manager. Ryan Giggs got exactly the same treatment and I would like to think he has been able to play at the highest level for 14 years simply because we watched what we did with him when he was a boy."

Ferguson has been forced to use Ronaldo to a greater extent than he would have liked due to a succession of injuries.

Ruud van Nistelrooy will miss out for the third successive game because of a knee problem, although Ferguson said the Dutch striker would be fit for Saturday's trip to Portsmouth. "He did a bit of training today but there is no need to rush him, so we will get him ready for Saturday," Ferguson said.

Roy Keane is set for a recall, while Louis Saha is expected to keep his place even though he is still nursing an Achilles injury.

Leicester have only managed one win at Old Trafford in 30 years, but Ferguson is aware that Micky Adams' side are more than bottom-of-the-table scrappers and may prove a tough test on a cut-up pitch he wanted to relay earlier in the season.

"Attacking-wise, Leicester are a real handful," he said. "They are the third top scorers away from home in the entire League, so our defence has a job to do. Also, the pitches are starting to get a bit livelier now, so games are becoming more unpredictable and the flow is not too good.

"We had a new pitch ready for us in Lincoln but when we wanted to move it, the frost had set in and we couldn't do it."

Adams is awaiting news on the fitness of the striker Les Ferdinand, whose knee injury kept him out of Saturday's 2-0 home defeat to Fulham. And although Lee Morris is close to full recovery from a thigh problem, he will not be fit in time for today's game, while the defender Callum Davidson is also sidelined by long-term groin and pelvic problems.