O'Connor, the nation's top fancy for the Tour, had to pull out after just nine stages, his hopes effectively finished early in the race when he crashed and had to ride on with an incredibly painful torn glute muscle.

But the AG2R Citroen ace is back, feeling confident for the Spanish tour and with his fellow Perth star Jai Hindley out to challenge for his second Grand Tour of the year after his Giro d'Italia triumph, Australian hopes are rejuvenated.

Last year, Bahrain Victorious's Jack Haig finished third overall, only the second time an Australian had ended on the GC podium at the Vuelta in 76 editions, after Cadel Evans' third place in 2009.

But the team revealed on Wednesday that Haig has not been included this year as he's still recovering from his own crash at the Tour in July.

O'Connor's return however makes him one of the race favourites in the bid to dethrone three-time defending champion Primoz Roglic (Jumbo-Visma).

"Ben's physical condition is good, he has prepared well. He comes to shine on the Spanish roads and to be among the best riders. Ben has the ability to excel in the general classification," said Julien Jurdie, AG2R's sporting director.

Hindley too must be considered a serious threat for the title as he sets out as part of Bora-hansgrohe's three-pronged GC assault alongside Dutchman Wilco Kelderman and Colombia's Sergio Higuita.

"It was really cool to win the Giro in my first year so I guess it does take a bit of pressure off, but at the same time I won the Giro, so now the expectation is for me to back up that performance and I'm up for that challenge," Hindley told reporters on Wednesday.

"It's just like going into the unknown, I guess. I've never done two grand tours in one year."

There are plenty of reasons to hope for more Australian success, with a total of 16 riders in the field altogether, including Team BikeExchange-Jayco's half-dozen home hopes spearheaded by sprint prospect Kaden Groves, who's fancied to win a maiden Grand Tour stage.

Rohan Dennis, fresh from his Commonwealth Games gold, will be looking for another time trial win on stage 10 and will be a key lieutenant of Roglic in the mountains.

THE 16 AUSTRALIANS AT THE VUELTA

Ben O'Connor (AG2R Citroen, age 26)

Jay Vine (Alpecin-Deceuninck, 26)

Robert Stannard (Alpecin-Deceuninck, 23)

Jai Hindley (Bora-hansgrohe, 26)

Miles Scotson (Groupama-FDJ, 28)

Luke Plapp (INEOS Grenadiers, 21)

Rohan Dennis (Jumbo-Visma,32)

Chris Harper (Jumbo-Visma, 27)

Jarrad Drizners (Lotto Soudal,23)

Harry Sweeny(Lotto Soudal, 24)

Kaden Groves (Team BikeExchange-Jayco, 23)

Kelland O'Brien (Team BikeExchange-Jayco, 24)

Callum Scotson (Team BikeExchange-Jayco,26)

Lucas Hamilton (Team BikeExchange-Jayco, 26)

Michael Hepburn (Team BikeExchange-Jayco, 31)

Luke Durbridge (Team BikeExchange, 31)

Australian Associated Press