Ewan, now 21, has always been viewed as a can't miss prospect from a very young age and confirmed those early assessments to progress through the ranks and become a fully fledged WorldTour rider with the Australian outfit.
This year he has tasted success at races like the Tour de Langkawi (two stages and first overall in the points classification) and the Tour of Korea, where he dominated with four stage wins.
But the Vuelta start marks a step up for the dimunitive speedster, where he will go head to head against the likes of Peter Sagan (Tinkoff-Saxo), Nacer Bouhanni (Cofidis) and John Degenkolb (Giant-Alpecin).
O4rica-GreenEDGE sports director Neil Stephens said the Ewan will be at the start line for the experience and will not ride the entire 21 stages of the race.
“This is a natural progression for Caleb, going onto a Grand Tour,” Stephens said. “But as we do with all of our young guys, we will certainly support him and have high hopes, but any pressure will only come from himself.”
“As a team we just want him to get out there for the experience. He will ride half of the race as a maximum, if not only a week to ten days.
“We have some great riders to guide him through. Right from how he should handle the pressure before the race and the team presentation, to how to handle the media, the press conference and all the other little pressures that come with a Grand Tour.”
The team will be led by veteran performers Simon Gerrans and Daryl Impey but it will look to Colombian climber Esteban Chaves for a high placing on the general classification.
The 25-year-old Chaves returns to the Vuelta a Espana after an altitude stint at home in Colombia.
“We would like to get Esteban in the top ten on the general classification, Stephens said. "When you look at the line up for the Vuelta there are some really good bike riders and to run top ten here would be something pretty huge.
“Last year we had a bit of a play around with general classification with Esteban. In the first week or so he was around the top six or seven riders before he cracked.
“I think his progression has been good. He rode through the Giro d’Italia, he went on to a great overall result at the Tour de Suissed and we are hoping to get a good general classification result with him here.”
Mathew Hayman, Cameron Meyer, Mitch Docker, Damien Howson and Jens Keukelere round out the rest of the Vuelta a España line-up for Orica-GreenEDGE.