Former England captains Alan Shearer and Terry Butcher have suggested Rio Ferdinand's injury blow could have a detrimental effect of the side's chances at the World Cup finals in South Africa this summer.
The Manchester United defender was ruled out of the showpiece event after injuring a knee in the first day of training at their base in Rustenburg on Friday and Shearer feels his absence could prove key.
Speaking to BBC Radio Five Live, he said: "If there's one player you really don't want to lose it's Wayne Rooney but after that I think there's three or four - (Steven) Gerrard, (Frank) Lampard, Ashley Cole and Rio Ferdinand.
"And unfortunately one of them, the captain, has now gone down in the very first training session. It's a big, big blow for England's chances."
Meanwhile, Butcher believes Tottenham Hotspur man Ledley King has all the attributes to step into the breach for the Group C opener against USA on June 12.
"For him to be out is a hammer blow and is something England could well do without," Butcher said to Sky Sports News.
"I've never heard of injuries before in training sessions in the build-up. I know competition's pretty fierce but it was obviously too fierce. Is the training too hard? Are the players too wound up, too keen?
"It's a psychological blow, because it's the first day, you've just touched down, he's the leader, and the players will look at that and say, 'Blimey, we'd better take it a bit easier and make sure no-one else gets injured'.
"Capello's plans are now up in smoke really. Ledley King is the main man now for me and should step in."