England will be without captain John Terry for Saturday's World Cup qualifier with Kazakhstan, coach Fabio Capello confirmed in his pre-match press conference.
Capello said: "It is a problem in the back for John Terry."
While the rest of England's 23-man squad went through final preparations at Arsenal's London Colney training base, Terry was having further treatment on his injury.
The Chelsea captain, who briefly visited the Stamford Bridge treatment room on Thursday, has not trained all week and will now shift his focus to being fit for Wednesday's encounter with Belarus in Minsk.
When asked if the centre-back would be fit for the second match of England's double header, Capello said: 'I don't know, it depends on his back. If he can train a bit the day after tomorrow then maybe, but we have good replacements."
Manchester United's Rio Ferdinand will take the captain's armband and the 29-year-old said: ''Being captain in any game is great, but leading out England in the first World Cup qualifier at Wembley is very special.
''I am very much looking forward to it. I will cherish this moment. The biggest thing will be walking out at Wembley. It is a fantastic new stadium and the home of our national team.
''To lead England out against France in Paris was great, but I think this will up the ante even more.
''Being at home in front of a sell-out crowd, in front of our own fans, my family there as well - I can't wait.''
Although understandably elated to get the job, Ferdinand is sorry Terry will miss out, recognising the hole it will leave in England's defence.
However, with Matthew Upson, Joleon Lescott and Wes Brown all candidates to replace the Chelsea man, Ferdinand is confident England will not be hampered too much against the eastern Europeans.
''John is a top player and to miss anyone of that calibre is disappointing,'' he said.
''But there are pros and cons to every situation. He is out of the team through injury, which is disappointing, now someone else has to come in and throw their hat into the ring.
''Whoever the manager deems right to play will go in with every confidence and produce the goods.''
Lescott replaced Ferdinand in similar circumstances for the win over Andorra last month while Brown, who played at right back against Croatia in Zagreb, is used to playing with his United team-mate at Old Trafford.
Capello would not reveal who will fill the vacant role but said: "We have plenty of players, we have the substitutes, I am sure the substitute of John Terry will play well.''
It is believed Capello intends to recall Steven Gerrard in place of the injured Joe Cole and switch England to a more attacking 4-3-3 formation against Kazakhstan at Wembley.
That move would enable hat-trick hero Theo Walcott to push further upfield alongside striking duo Wayne Rooney and Emile Heskey.
Capello's task has not been made any easier by Kazakhstan changing manager and dropping players - meaning it is a step into the unknown for England.
"I saw three games but it's all changed and now I know nothing," Capello said. "There are a lot of young players coming from under-21s and I know only four players.
"It's better if you can know everything about your opponent and it's always different against a new manager but it is impossible to change their style completely."