Paul Scholes' hernia problem will almost certainly rule him out of England's forthcoming Euro 2004 qualifiers.
Scholes is a key man for England
The news will come as a blow to coach Sven-Goran Eriksson, who is due to announce the England squad for the matches away to Macedonia and home against Liechtenstein on Sunday.
Sir Alex Ferguson is reported to have told Eriksson on Saturday about the extent of Scholes' problem.
"Paul will be out for at least four weeks," said Ferguson.
"We will leave it for seven days to see if it settles down.
"Because it would be his third operation on the same problem, our surgeon is reluctant to operate right away, so we'll have another look after a week to see if he needs surgery.
"If so, he would be out for six weeks. Otherwise he will be given a further three weeks rest."
The timing of the announcement is likely to fuel rumours of tension between Manchester United boss Sir Alex Ferguson and Eriksson after Scholes played for an hour in England's recent friendly against Croatia.
Ferguson said Scholes "was in a real state" after that match, despite telling the England staff about his hernia troubles.
But Eriksson said neither Scholes nor Manchester United had expressed any concerns about the midfielder's fitness, and that he agreed with the player to give him an hour on the field.
Ferguson played Scholes for 90 minutes against Newcastle - three days after the England-Croatia match - with the midfielder scoring the winning goal.
"It's not easy to find another Paul Scholes, if you want to find the qualities he has," said Eriksson.
"We don't have a second Scholes in England."