Defoe was preferred to Andy Johnson for a place on the plane as Eriksson keeps his options open before Rooney returns to Manchester for a scan on his broken foot on Wednesday.

"Defoe goes with us to Germany because we have to be insured about Wayne Rooney," Eriksson said.

However, the Swede is defiantly optimistic Rooney can recover in time from a double fracture suffered against Chelsea on April 29 to play some part in the finals.

"Obviously, everybody thinks he will come back from Manchester on Wednesday evening and that's what I think," Eriksson said. "I have no doubts about it -- but I can't be sure, of course, until the scan is done."

Under FIFA rules, Eriksson has until 24 hours before their opening Group B game against Paraguay to replace Rooney in his squad, should the 20-year-old be ruled out of the finals.

Eriksson saw several reasons to be upbeat about England's chances in Germany, having steered them to only quarter-final places at the 2002 World Cup and Euro 2004.

"Today, everything is more or less perfect," said the Swede.

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"The spirit in the squad is absolutely fantastic, even better than it's been before -- and before it's been very good. There is a great belief that we can do very well.

"Fitness-wise we are much better, football-wise we are much better. So I think we are ready for the World Cup ... and I think we can be better and better with every game.

"We haven't reached our pitch in this moment but we will."

After Paraguay, England's Group B campaign continues against Trinidad & Tobago and Sweden.