Full match preview Beckham criticises FA

King, who has been playing in midfield for Spurs recently, will partner Gareth Southgate in central defence after Sol Campbell and John Terry both withdrew.

"It was a bit of a shock to be called up," said the 23-year-old.

"I thought because I was playing in midfield for my club my international chances would be slipping away, so this is a big boost for me."

"I still consider myself as a defender and I know that, in the long term, that is where I have the best chance of playing for England," King added.

Coach Sven-Goran Eriksson was forced to reshuffle his side and call up King after Campbell decided not to travel to Portugal.

Terry - a straight choice for England in the absence of the banned Rio Ferdinand - would probably have been partnered by Southgate in Faro.

But the Chelsea player did not fly out to Portugal after aggravating a shin problem during training.

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Eriksson believes King can make the switch from Tottenham midfielder to England centre-back: "Is King ready to start? I hope so - and the answer on that one we will have on Wednesday. But I think he is.

"It will be good to see other players. We are a little bit unlucky with the four who are out - Ferdinand, Campbell, Terry and Woodgate - all extremely good central defenders - not only in England but in Europe.

"I hope to have Terry, Woodgate and Campbell ready for the Sweden game at the end of next month and for the two games in June before the finals.

"It will be very important to go into the championships knowing who the two at the back are that will be starting. On Wednesday it will be a completely new partnership," he said.

Striker Darius Vassell also pulled out on Tuesday with a stomach upset but there was better news for Eriksson as skipper David Beckham has shaken off a slight knock and will definitely play.

The Swede is expected to pick his first-choice strike partnership of Liverpool's Michael Owen and Everton's Wayne Rooney with Emile Heskey and Alan Smith on the bench.

Vassell said: "I'm extremely disappointed at having to withdraw from the England squad.

"I was really looking forward to playing some part in the game against one of the contenders for this summer's European Championship, but unfortunately this illness has really taken it out of me.

"But now I hope I can recover in time for the weekend to face Birmingham City in the local derby and continue my recent good run of goalscoring form, so I can keep myself in Mr Eriksson's thoughts."

Eriksson seems set to ignore Fifa criticism and make a rash of half-time substitutions.

There could even be an entirely different England line-up in the second period, with Eriksson defending his policy against protest that mass replacements turn friendly games into farce.