The surgery will shift Gerrans' early season focus to the Spring Classics beginning in March as he ensures a complete recovery.
After working hard throughout the off-season, the 34-year-old is disappointed to get so close to the Australian season, and a national championships and Tour Down Under defense, and need to withdraw.
"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.
"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."
After completing an interval session on the road bike from Mansfield to Mt Buller on Sunday, Gerrans then switched across for a couple of hours on the mountain bike, a common cross training activity in the off-season.
"About half way through my mountain bike ride I became a little unstuck, came down and landed pretty heavily on my left side," he explained.
"I knew straight away as I hit the ground that I had broken my left collarbone.
"From there I had a little bit of a walk to get down to a point where I was picked up by a four-wheel drive and went directly to Mansfield hospital to get cleaned up and have the x-ray to confirm."
Post-surgery, Gerrans is expected to take a week to ten days off the bike to heal, before rebuilding for another assault on the world cycling calendar.
Sport director Matt White said the injury was a blow for Gerrans and the team on the eve of the 2015 season but expects both to bounce back to make the most of the situation.
"Simon is one of our key riders and the Australian summer, particularly the national championships and Tour Down Under, were a real goal for him again next year," White said.
"As always he had worked very hard to get himself into peak condition and that is disappointing for him to have it go somewhat to waste. But he is the ultimate professional; he will be back on the bike in no time and hunting down his next victory before we know it."
Gerrans had one of the strongest overall seasons of his career this year, enjoying a splendid summer in Australia with victories at the Santos Tour Down Under and the National Championships before heading to the Ardennes where he became the first Australian in history to win Liege-Bastogne-Liege.
For his efforts Gerrans was awarded the Australian Cyclist of the Year award, and was voted the People's Choice by Cycling Australia members.