Fans will be locked out of today's Derby as Western Australia tries to contain the latest COVID-19 spread.

45,000 fans were expected to attend today's clash but WA Premier Mark McGowan said the game posed too much of a risk for the state.

“We have made the decision to not permit spectators attend the Derby this afternoon,” McGowan said in a press conference reported by The Herald Sun's Jon Ralph.

“I understand people will be disappointed and some people will be frustrated by the decision has been made on health advice and we have tried to communicate this as quickly as possible.

“Having 45,000 people try to get to Optus Stadium at the same time is too much of a risk, especially as we are still going through the close contacts.”

The announcement will come as a huge blow for West Coast and the AFL who were expected to make over a million dollars in revenue from the clash.

It is the second week in a row that WA fans have been locked out of Optus Stadium after Fremantle played North Melbourne in front of empty seats.

Western Australia recorded three new COVID-19 cases on Saturday but no new cases overnight.