Rain and storms are forecast for Sydney on Sunday afternoon. If true, they look like robbing the showpiece game of a bumper crowd.

"My understanding is with the pre-sales we've got, we'll certainly get 20,000. If we get fine weather we could get into the high 20s," head of football Stefan Kamasz told au.fourfourtwo.com at Saturday's NYL clash in Sydney.

Never before has three competition points been so important. At stake in Sunday's game is the 2009/10 Premiership, a berth in the 2011 Asian Champions League (and the winner of that qualifies for the Club World Cup), state versus state bragging rights and a psychological edge going into the finals series.

"It's in the lap of the Gods now. We should move our ground to Warragamba Dam," he joked.

Sydney had their final workout on Saturday morning at their Macquarie University base. Brendan Gan has been promoted to the squad while Mark Bridge misses out due to a toe problem.

The Premiers Plate trophy will be at the stadium on Sunday and will be presented to the home side if they win the game.

If Victory triumph, it's likely the trophy presentation will happen in Melbourne at a later date.

The Premier of NSW Kristina Keneally will also be in attendance at the SFS for this huge game.

The referee for the clash will be Matthew Breeze.