BOTH preliminary finals appear unlikely to be interrupted by rain, with just a five percent chance of any precipitation at either the MCG or Optus Stadium.

Warm conditions are forecast for the first ever preliminary final at Optus Stadium on Saturday, where West Coast will host Melbourne.

With the contest taking place in the middle of the day to allow Melbourne's players to get back to Victoria swiftly if they win, temperatures could top 25 degrees during the game.

The forecast for the MCG on Friday night shows only the very slight possibility of any rain, which is sure to please the capacity crowd that's expected.

With Tigers and Magpies club members snapping up all available tickets within two hours, public sales were cancelled for Monday afternoon.

AFL members' tickets sold out within 30 minutes on Tuesday morning.

Melbourne Cricket Club members will hold the possibility of a 100,000 crowd in their hands, with up to 13,000 seats available for walk ups on Friday.

Security will be tight as it has been for all major games at the MCG this year, with parking in Yarra Park limited to pass holders.

While it will be Optus Stadium's biggest game in its short history, the venue confirmed its security arrangements would be the same, and it was "business as usual".

However, the AFL and Channel Seven have worked to provide a live feed of Melbourne's Federation Square live site to operators of the Optus Stadium scoreboard, with Demons fans back at home set to be shown on the big screen in the west at select times throughout the afternoon.

FINALS FORECAST 

Richmond v Collingwood, Friday September 21 at the MCG, 7:50pm AEST MCG

Partly cloudy. Five per cent chance of any rain. Min 8. Max 18
Tickets: Exhausted, other than 13,000 MCC walk ups
Parking: No public parking, limited for passholders/disabled
Transport: https://www.ptv.vic.gov.au/ Free tram zone extended to the MCG
Channel 7 commentators: Bruce McAvaney, Brian Taylor, Wayne Carey, Cameron Ling, Daisy Pearce, Matthew Richardson
Simulcast on Fox Footy and Telstra AFL Live App 

West Coast v Melbourne, Saturday September 22 at Optus Stadium, 1:20pm AWST

Partly cloudy. 20 per cent chance of any rain. Min 9. Max 25
Tickets: Exhausted
Parking: Limited. Fans advised to take train or walk across bridge from city
Transport: https://www.transperth.wa.gov.au/
Channel 7 commentators: Luke Darcy, James Brayshaw, Matthew Richardson, Peter Bell
Simulcast on Fox Footy and Telstra AFL Live App