Jay Vine's wife has revealed how she feared he might have died when the star Australian cyclist was lying prostrate in a ditch after a dreadful crash in the Itzulia Basque Country race.

But Bre Vine, a cyclist herself, predicted that his fighting spirit, as he recovers in a Spanish hospital after suffering fractured vertebrae, would ensure the UAE Team Emirates rider will return to the saddle "stronger than ever".

The team reported after Thursday's crash that the 28-year-old from Canberra had been left with "a cervical and two thoracic spine vertebral body fractures" as he came off perhaps worst of all the big-name riders in the mass incident in northern Spain.

Double Tour de France champion Jonas Vingegaard suffered a collapsed lung, a pulmonary contusion, broken ribs and a broken collarbone, with his title defence in doubt, while double world champ Remco Evenepoel needed surgery on a fractured collarbone and shoulder blade.

Bre, who is pregnant, watched in horror as television images showed Jay being treated while motionless at the side of the bend where he had slid off.

"I will admit when I saw the live coverage of him just lying there not moving for such a long time, I genuinely wasn't sure if I still had a husband and if the worst had happened," she posted on Instagram.

"As soon as the team had comms it was communicated to me ASAP. And I'm so genuinely grateful for how quickly they got the news to me."

She said she jumped in her car at their Andorra home and arrived at the hospital's ICU six hours later.

"I will let UAE share his medical updates when we have determined the extent of the injuries. But for now he is 'okay', and we are still considering all our options. The team are making sure he and I are getting the best care possible," she added.

"There's a lot to unpack from the incident, and we will have discussions with the relevant people later on, but for now my focus is on our family and helping Jay through this.

"I've followed every single kilometre Jay's raced and trained, I've seen every crash, and every triumph.

"This crash is going to be one that sticks with us for a long time, but like Jay has done every single day before, he will fight and come back stronger than ever with the #getwreckedjay Spirit that we love.

"It's an odd phrase I'll give you that, but goes back to all those years ago when we were racing mountain bikes, and long story short: It means give it everything you've got, shit will happen and things will go wrong, but keep fighting.

"And that is what this man continues to do on a daily basis and we will do again together."

Vine's rise has been one of cycling's most inspiring, after he was discovered as an e-sports specialist, before being snapped up by a pro cycling team and becoming a Grand Tour stage winner and Tour Down Under champion.

But days after starting the Basque tour with a brilliant second place in the time trial, this latest in a catalogue of injuries he has suffered will keep him out of the Giro d'Italia, where he would have been one of Tadej Pogacar's key lieutenants in the mountains.

Double Tour de France champion Pogacar offered his best wishes to his teammate, whose Olympic hopes for 2024 are also surely over.

AAP