Spratt was in doubt for Saturday's race in Imola due to an injured right shoulder and concussion suffered when she crashed in the Giro Rosa last week.

Cycling Australia confirmed on Thursday that she is unable to compete with the 33-year-old's place in Australia's team taken by Tiffany Cromwell.

"Right now it feels pretty devastating that I am not well enough to be able to race the worlds," Spratt said in a statement.

"My shoulder is recovering well but unfortunately, my concussion still needs some time."

Spratt took took bronze in last year's world championships road race after silver in 2018.

"The worlds was a huge target so it's hard to come to terms with knowing the form was exactly where it needed to be," Spratt said.

"But at the same time I am grateful that I have a team around me that prioritise my health and wellbeing."

The women will tackle 2,750 metres of climbing over their 144km course in Saturday's world championships road race.

AUSTRALIAN TEAM AT ROAD WORLD CHAMPIONSHIPS

Women's Road Race

Grace Brown, Tiffany Cromwell, Brodie Chapman, Lucy Kennedy, Shara Marche (nee Gillow), Rachel Neylan, Sarah Roy (Mitchelton-Scott)

Men's Road Race

Simon Clarke, Luke Durbridge, Chris Hamilton, Jai Hindley, Damien Howson, Michael Matthews, Richie Porte, Nicholas Schultz

Women's Time Trial

Grace Brown

Men's Time Trial

Rohan Dennis, Luke Durbridge

Australian Associated Press