UPDATE 3:13pm: MISBEHAVING soccer fans have been threatened with fines - and even the lock-up - in a World Cup crackdown by police.
Up to 18,000 people are expected to pack Birrarung Marr to watch the Socceroos take on Germany from 4.30am tomorrow.
Two big screens, erected at the Yarra-side precinct this afternoon, will beam the action live from South Africa.
However police have warned drunken louts - and especially flares - will not be tolerated.
Acting Assistant Commissioner Andrew Crisp said a "significant police operation'' involving uniformed and plain-clothed officers, as well as mounted and water police, would be patrolling Birrarung Marr.
"It is an alcohol-free area,'' Acting Assistant Commissioner Crisp said.
"If you are caught with alcohol, you will face a $100 fine. If you are drunk, or drunk and disorderly, or just basically muck up, then you will face a $234 fine and also possibly get locked up.
Lord Mayor Robert Doyle predicted cold weather and the early-morning hour would not stop Melburnians gathering for the Socceroos' first World Cup clash."(And) we want to make the point that if you are caught with a flare, if you dare let off a flare, then you will be caught, you will be charged, and you will appear before the courts.''
"I think people in Melbourne turn out anyway,'' Cr Doyle said.
"They turn out whether it's a public holiday, whether it 4.30am, whether it’s raining or not. We're just very keen sports spectators.''