Rio Ferdinand has been ruled out of Sunday's Carling Cup final between Manchester United and Aston Villa and seems unlikely to be fit to captain England against Egypt at Wembley next week.
The Red Devils defender had been expected to play in tonight's 3-0 win over West Ham after a recent suspension.
However, Alex Ferguson claimed the 31-year-old felt a problem in his troublesome back this morning which now means another spell on the sidelines.
"He tweaked his back in training and he won't be ready for Sunday," said Ferguson.
"It is unfortunate for him that he's going to miss a couple of games."
Aside from missing a major Wembley showpiece, it also looks likely to cost Ferdinand the chance to lead his country into their final friendly before Fabio Capello names his provisional World Cup squad given Ferguson is determined not to take any risks with the former West Ham star.
"Rio has been training great too," said Ferguson.
"There have been no mishaps at all. But when you get these twinges you can't take a chance."
It was also a bad night for Brazilian midfielder Anderson who, making his first appearance for over a month, suffered what appeared to be a serious knee injury during the first half.
"We have sent him for a scan," said Ferguson.
"Hopefully it is not too serious but it did not look good."
The fitness problems, especially those that appear set to make Steven Gerrard captain for Fabio Capello's side next week, only partially overshadowed another two-goal contribution from Wayne Rooney to United's 3-0 win.
Rooney is now on 27 goals for the season, 15 fewer than Cristiano Ronaldo managed in his legendary campaign that saw him crowned world player of the year two seasons ago.
"He has been watching my videos," laughed Ferguson of Rooney's two headers.
"They were two excellent headers, although there was also some good play from Antonio Valencia."
Ferguson had in fact paid Rooney more fulsome praise in his programme notes, so it was left to Gianfranco Zola to offer a more honest appraisal of the striker's latest work.
"Everything he touches is turning to gold at the moment," said the Hammers chief.
"He is in the kind of form that means every single opportunity can become a goal.
"I thought he had a normal game. But he scored two goals and he might have had another one, which tells its own story.
"Having a player like him helps any situation. One man cannot do it all on his own. But he can make a big difference."
Michael Owen added a third, his first goal since scoring a hat-trick against Wolfsburg in December, to seal a win that took United to within a point of leaders Chelsea and put them in good heart ahead of their Wembley encounter with Aston Villa on Sunday.
"We had to win," conceded Ferguson, who is now set to recall Darren Fletcher and Rafael Da Silva amongst others.
"There will be changes on Sunday now.
"I have done that all along in the competition and I will have to look at the situation to make sure we have a fresh team."