DUBLIN: Manchester United defender John O'Shea is set to miss the rest of the season with a leg injury, manager Sir Alex Ferguson said Thursday.

O'Shea suffered a suspected dead leg playing for the Republic of Ireland during their controversial World Cup playoff defeat by France in November but the injury has proved more severe than first thought.

Ferguson told Thursday's Irish Independent: "He's got a terrible injury at the moment. It's one of those sorts of injuries that are unusual. It's like a dead leg except a dead leg is usually only three or four days.

"The problem is that the blood clot became all knotted and when it gets knotted you get calcification so therefore it's a long process to clear that up and he'll probably miss the season now.

"It's a bad blow for the boy and for the team because he can play anywhere."

The 28-year-old O'Shea has demonstrated his versatility by playing across the back four for the English champions as well as in midfield.

His injury has prevented O'Shea establishing himself as a first-team regular just when fitness problems involving United defenders this season gave him a chance of nailing down a place in the team.

Ferguson was in no doubt of what would have happened to O'Shea this season had the player avoided injury.

"When you look at all the problems I've had with the back four, he could have played every single one," said the United boss.

O'Shea will also miss the Republic's friendly with Brazil at Premier League Arsenal's Emirates Stadium on March 2 and an end-of-season training camp.

Ferguson said the upcoming friendly date was an annoyance for club managers and questioned its worth to international bosses ahead of June's World Cup in South Africa.

"I don't even think the international managers think they're all that important now. They never play their full team and there's always drop outs."