Simon Gerrans will be unable to defend his Tour Down Under title next month after breaking his collarbone during training on Sunday.
Gerrans will undergo surgery on his left collarbone on Monday, meaning he will miss the Australian National Road Race Championships on January 7 - where he also would have been defending champion, the Tour Down Under in South Australia from January 17 and the inaugural Cadel Evans' Great Ocean Road Race on February 1.
Due to previous form and his classics pedigree, the 34-year-old would have been considered a serious contender in all three races but will now aim to be ready to defend his Liege-Bastogne-Liege title in April.
"Unfortunately it doesn't matter how well the recovery goes from here, I don't think I am going to be in any condition to be racing at a high level in January," Gerrans said in a statement on his team Orica-GreenEDGE's website.
"With that in mind I think it is better to take my time, make sure the recovery goes well and get all the rehab done so I don't have any ongoing issues.
"It's a big blow not to be able to line up in the national championships and Tour Down Under and defend my titles. They are races that I really enjoy and I know how important they are to the team.
"Looking on the bright side, what it does do, is force a bit of a break now and mean that I can work towards some goals later in the season and be a lot fresher."
Gerrans added on Twitter on Monday: "Heading in for surgery. Thanks for the messages."
The Melbourne-born cyclist was riding a mountain bike in northern Victoria on Sunday when he crashed.
"About half way through my mountain bike ride I became a little unstuck, came down and landed pretty heavily on my left side," Gerrans said.
"I knew straight away as I hit the ground that I had broken my left collarbone."
Orica-GreenEDGE sport director Matt White was clearly disappointed to have lost the reigning Australian champion ahead of the start the 2015 UCI World Tour but insisted his team will find other options to ensure they challenge for titles at the three upcoming races in Australia.