Star attacker Harry Kewell says he's ready to be the Socceroos' medical miracle at this World Cup.

Kewell has slammed suggestions his long-standing groin problem and lack of match fitness will make him a liability in the opening match against Germany in Durban on Sunday (Monday AEST).

And the 31-year-old says despite playing less than five minutes of football since January, he will be ready to start against the Germans if coach Pim Verbeek gives him the nod.

"I'm definitely ready to start," Kewell said on Sunday.

"I know everyone's speculating about this, that and the other, but it's the manager's choice.

"You work with this medical system and these medical staff, they're fantastic. They know what they're doing.

"Everybody thinks you come to this thing (the World Cup) and then that's when they start working.

"But they knew about my injury 14 or 15 weeks ago. We were working then, when everyone was asleep, when everyone was awake.

"All these questions of me not being fit are just people commenting on things they don't know of."

Kewell has had team physiotherapists Les Gelis and Phil Coles as his constant companions.

Both have shadowed him throughout lonely running and light ball work sessions away from teammates for the majority of Australia's pre-World Cup training camps in Melbourne and South Africa.

Their healing hands readied Kewell for a return to full training last Thursday, though he has had just two sessions with the rest of the Socceroos.

While Verbeek named him as a substitute for the 3-1 defeat by the United States in Roodepoort, the Dutchman resisted tempting fate.

Instead Kewell's day of reckoning should come on Sunday against a German side he believes will provide a searching test of the Socceroos' fighting qualities.

"We all know throughout the qualification they (Germany) can not be a great team, but as soon as they head into a competition mode, they step up four or five gears," Kewell said.

"They become this team that no one can seem to beat. But we're going to be up for it.

"We're at a World Cup and we're expected to play the best teams, and Germany are one of them."

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