Mourners prepare to say goodbye to Robert Enke

The current national squad will also be present at the service for the Hannover goalkeeper, who committed suicide on Tuesday.

The service, which will be followed by a private burial, is expected to be attended by 45,000 mourners at the Niedersachsen Stadion and will be screened by Germany's state-run television station, ARD.

"It is for a very sad reason that so many former colleagues of Robert Enke have spontaneously contacted us to join together with the national team in his farewell," said Germany's general manager Oliver Bierhoff.

"However, it is an indication of the togetherness of our team and the friendship among the players which I and the coach are very happy about."

Bayern Munich striker Miroslav Klose may be forced to miss Sunday's ceremony, however, after being quarantined because his twin sons Noah and Luan have contracted the swine flu.

Enke took his own life after a battle with depression, an illness he had managed to keep secret from all but his closest family and friends and even managed to hide from the national team's psychologist, Hans-Dieter Hermann.

In an interview on the German Football Association's (DFB) website, Hermann revealed he had examined Enke in September, but found nothing untoward.

"Robert was complaining about an exhaustion syndrome," he explained.

"Just to rule it out, I also looked into a potential depression.

"In a one-hour session, there was no indication whatsoever of this illness. Quite the opposite Robert described himself, apart from his tiredness, as a happy man with clear ideas for the future, both privately and with sport.

"Of course I ask myself today, like everybody, if I should have realised something if I had maybe been a bit stronger with my questioning, but what I didn't know is that he was already in treatment and already in the right hands."

In fact, Enke managed to keep the true extent of his depression a secret from his own psychologist in the weeks before he committed suicide.

In a note he left behind, he apologised for defying his doctor by making things out to be better than they were to enable him to go through with his suicide attempt without raising suspicion, and leaving more questions than answers about his death.

"Nobody can really answer the question 'why?'," added Hermann.

"The way the drama evolved leads to the conclusion that Robert must have found himself in a particularly hopeless situation with no way out in his last few days."

Germany are exploring the possibility of staging a friendly, possibly against Hannover, in honour of Enke - a suggestion which came from his team-mates.

"The players have already approached us with suggestions as to how we can pay tribute to Robert Enke," said DFB general secretary Wolfgang Niersbach in the Bild newspaper.

One of those suggestions, according to the Bild, is to stage a friendly at the Niedersachsen Stadion in January or February.