The 35-year-old Mitchelton–Scott rider will again lead his team as he tries to back-up his victories in 2018 and 2019.

Impey, who won an individual stage of the Tour de France last year, told AAP: "There's no doubt it's one of the favourite races on the calendar for me and it's an important race for our team.

"It's similar to last year, same kind of strategy, we put in all the hard work in December.

"I don't feel the pressure that I need to do the 'three-peat'.

"It would obviously be great, but I think I'm just going to take it day-by-day."

The race, the opening event of the 2020 International Cycling Union World Tour, starts with a 150 kilometre flat stage to and from Tanunda tomorrow.

Six stages will be held in all leading up to Sunday's (January 26) finish in Willunga Hill.

A course which favours the climbers more than in previous years has been predicted.

Impey's rivals will include Australia's 2017 champion Richie Porte, riding for Trek-Segafredo.

He will be supported by Danish team-mate Mads Pedersen, the reigning world road race champion.

Britain's 2018 Vuelta a España champion Simon Yates will also ride for Mitchelton-Scott while home Australian rider Rohan Dennis should be a threat for Team Ineos.

Elia Viviani, the European road race champion, will see action for Team Cofidis while Romain Bardet, a multiple Tour de France stage winner, will lead AG2R La Mondiale.

Earlier this month, it was confirmed that the Tour Down Under would still go ahead despite the bushfire crisis in Australia.