© Press Association 2010.

Former England winger John Barnes has warned it is "unrealistic" to expect the national team to beat the likes of Spain and Brazil and win the World Cup.

World Cup fever has gripped the nation with England's impressive qualification campaign feeding the optimism ahead of the finals in South Africa.

Barnes, though, insists reaching the quarter-finals or semis would be a fair reflection of England's standing in the game and being unable to go further would not be a failure.

The Liverpool legend said: "Can we say, hand on heart, we are going to beat Brazil?

"I say we can beat them, but to expect to beat them is unrealistic."

He added: "You have to maximise the potential of the team and Fabio Capello has done that, qualifying in style and playing well in most of the matches.

"He has played against Spain, Brazil and France and lost those matches but he has maximised the potential.

"If he maximises potential he will get to the semi-finals and with a bit of luck, we can go to the final.

"They can win the World Cup - but we shouldn't expect them to.

"Maximising potential doesn't mean winning it because if everyone else does too, the best team will win, the second best team will come second, etc.

"From the draw it looks like if Brazil don't get knocked out and we don't, we could meet each other (in the semi-final or final).

"If Brazil maximise their potential, they will beat us.

"So what we have to do is maximise our potential and stop Brazil playing to theirs. Which we can do."