Eurosport - Mon, 21 Jun 16:45:00 2010
England must defeat Slovenia in their final Group C match on Wednesday afternoon to guarantee themselves a place in the knock-out stages.
Capello has his own thoughts on what has gone wrong within his squad.
"It is a mental thing. Absolutely. When you are under pressure, big pressure, sometimes the legs do not work normally," said Capello in an interview with the BBC.
England will be eliminated if they lose to Slovenia. A high-scoring draw could see them relying on a favourable result in the match between the USA and Algeria - a low-scoring draw - while a stalemate of 0-0 or 1-1 would also see the Three Lions knocked out if the USA win.
Algeria could qualify by beating America, should England - last eliminated at the first stage when Sweden hosted the tournament in 1958 - fail to win.
England won nine out of 10 games in qualifying for the finals and netted 34 goals - the highest number scored by a team in European qualifying.
Capello feels they must win the match.
"After this game we have no more chances. We have to win, " said Capello.
"Look, the results have not been good, but I haven't seen the spirit on the pitch for 90 minutes, only for five or six minutes.
"I hope in the next game the spirit will return on the pitch to that I saw in qualification."
The Italian coach claims the mood in the squad is good despite reports of disharmony.
He also said there was no meeting to "clear the air" after the draw with Algeria. Chelsea captain John Terry suggested the players planned to speak to Capello, with several reported to be unhappy over tactics.
Capello said: "The spirit in the hotel and in training is fantastic, it's incredible.
"The players are training really well, they are smiling and they are playing together and everything is like the best moment of their life. But I want to see this in the game and not just only in training.
"We have prepared everything perfectly for the players - they can swim, go to the gym and train.
"The players are free and can go where they want. Everything is more or less perfect. But we are here to play at the World Cup and not for a holiday."