By Phil McNulty
Chief Football writer in Cologne
Wayne Rooney's return to the England starting line-up against Sweden may prove the defining moment of their World Cup campaign.
Rooney's return could be the answer to England's prayers
After weeks of worry about what England would be like without Rooney, we are now about to witness what they are like with the 20-year-old talisman.
And once we have seen the effect Manchester United's young star has on a stuttering campaign from Sven-Goran Eriksson's team, their hopes of winning the World Cup can be placed firmly in context.
If Rooney emerges from the Sweden game unscathed and back to his best, then the optimism that has washed over this England squad since they arrived in Germany may actually prove justified.
If Rooney looks way short of match-fitness and is unable to sprinkle some magic on what have so far been two turgid performances, then all the private worries mounting about England's World Cup ambitions will only increase.
It is this simple fact that underscores the effect Rooney has on this England squad - both on the pitch and off.
Eriksson never makes any effort to hide his admiration for Rooney, words like "fantastic" and "perfect" spilling from the Swede's lips when his name is mentioned.
The word inside England's training camp is that the coaching team have been preaching the need for patience and the need to keep the ball, so Rooney's return is pivotal if they are to prove they are realistic challengers in Germany.
Rooney is the inspiration for the coach, his team-mates and the fans
Jamie Carragher speaks in awe of Rooney's ability in training, while fellow Scouser Steven Gerrard, not exactly short on brilliance himself, happily acknowledges Rooney as England's most influential player.
Rooney has been christened Wazza by his team-mates in an obvious reference to Paul Gascoigne, who has occasionally been compared in build and brilliance.
He is the loudest presence in the dressing room before games and the most mercurial when the action starts.
England's supporters also relate to the working-class background of a boy just born with a natural talent.
His very appearance on the big screens as he sat on the sidelines for the opener against Paraguay in Frankfurt drew an instant standing ovation.
In other words, Rooney is the inspiration for the coach, his team-mates and the fans.
And fortunately for England, it is a responsibility that sits easily on his shoulders.
Rooney is a commanding, confident presence on the pitch
But even Rooney still has to answer searching questions before he can feel he has made an impact at this World Cup.
He gave a mixed performance after coming on against Trinidad and Tobago.
Rooney blazed on to the pitch, produced a stunning pass for Ashley Cole, chased back into the left-back slot for a spot of unlikely covering - but appeared to run out of steam quite quickly.
He must also show his foot can stand the stress of serious combat and avoid the more sinister interventions of defenders, all while being seen as the man to provide England with the "extra gears" so many members of the squad tell us they have.
So we have the double dilemma of England's attacking duo.
Rooney must prove he is as fit as he says he is. Michael Owen must answer the critics who are suggesting he is no longer as good as he says he is.
Owen, for his part at least, has always answered those questions successfully and no-one would back against him doing it again.
Rooney is also crucial to Eriksson tactically, particularly given the lack of imagination shown in the first two games.
A succession of long balls towards Peter Crouch has been the main game plan, and no country will ever win a World Cup on that basis.
The return of Rooney opens up all sorts of possibilities for England to broaden their tactical scope and suggest they can seriously threaten the big guns in Germany.
Eriksson admits it himself: "He is very important, a fantastic player and that type of link player between the two strikers and the midfield that we need.
"We saw when he came on against Trinidad and Tobago that maybe he is not 100%, but he kept the ball up there and did some very clever movements and clever passes."
Rooney is exactly what this England team needs on every level, which is why his every move in Cologne will be regarded as a signpost to exactly where this so far unspectacular campaign is heading.