Manchester United are flying Norwegian defender Ronny Johnsen back from Copenhagen to clear up a knee problem that could threaten his World Cup dream.

The Old Trafford club are reacting to news from the Norwegians that they have discovered the defender has a damaged cartilage.

United may now lose the player for the rest of the season and Norway fears that unless prompt action is taken it could hit their World Cup plans.

The Norwegians, who play Denmark in a warm-up international today, want Johnsen to have an operation and even suggested that it could be done in Norway.

But United spokesman Ken Ramsden said: "He will be coming back to England sooner rather than later and we will have our medical people look at him.

"Any decision on an operation will be taken in the best interests of the club and, of course, the player. Clearly we are mindful of the importance to Ronny as far as the World Cup is concerned."

Johnsen is expected back at Old Trafford today and Ramsden said: "Whatever the situation, Ronny will have whatever is needed to be done here.".

Norwegian FA medical experts are suggesting that United missed the injury when Johnsen was carried off during the Good Friday clash with Liverpool.

He suffered a badly damaged ankle that day in the tackle that resulted in Liverpool's Michael Owen being sent off, but the Norwegians claim he picked up a knee problem earlier in the same match which was overlooked.

Norway's team doctor Trygve Kase said: "Ronny was in so much pain from the ankle it completely overshadowed the knee."

Johnsen's injury was discovered during training for the Denmark match and he was immediately ruled out of the match.

"I'm told it's a quick and easy procedure and I hope to be back for the game against Mexico on May 20th," he said.

But United insist it is their decision, not the Norwegians'. Meanwile, United goalkeeper Peter Schmeichel is poised to hand manager Alex Ferguson a boost and report fit for the rest of the championship race.

Schmeichel had to go off during Saturday's 1-1 draw with Newcastle at Old Trafford but is now hopeful of playing for Denmark against Norway today. The giant Dane was expected to be out for season with a thigh problem he now believes he can play on and said: "It is me alone who makes the decision. It is important for me to play this match and I am working day and night to be ready."

Jamie Redknapp has refused to concede that his chances of making the World Cup finals are over.

Although the 24-year-old Liverpool midfielder damaged medial knee ligaments during Sunday's Premiership game at Coventry City, he is adamant that he will play senior football again before the end of the season.

England's coach Glenn Hoddle has already said that any player unable to finish the domestic campaign because of injury would be unlikely to win a place in his final squad of 22 for France.

"I hope to be playing again before the end of the season," said Redknapp yesterday after returning to Merseyside to begin intensive treatment.