Clarke won the 2014 edition of the race by eight seconds ahead of Cameron Wurf (Cannondale), set up by his stage 3 win into Bendigo. The final day showdown up Arthurs Seat never eventuated due to the stage being cancelled with the threat of fire deemed too dangerous, handing Clarke the win.
"Sun Tour is going to be very different this year," Clarke explained. "Obviously last year there was a couple of WorldTour teams and we really raced each other. This year there is only us and that is really unfortunate. I don't know the circumstances behind it but we are really going to be marked.
"It's going to be similar to a national's situation where it's us versus the rest so we are going to have our work cut out and I think it's going to be a race where, although I'd like to defend, I think we need to defend it as a team."
The five stage 2.1 race starts with a prologue along Melbourne's Southbank with Sunday's final stage up Arthurs Seat set to decide the general classification. Clarke is anticipating the he will be seen as the rider to watch and the team will therefore need to prepare for several different scenarios.
"We have to leave our options open because 120 guys can easily just mark one GreenEdge rider so we are going to go in with a few options," he said. "Cam [Meyer] is going really well, Damien Howson … we have some good guys there and as much as I'd like to defend it, as long as we defend it as a team, then I think it will obviously be a successful result."
At this stage of the season last year, Orica-GreenEdge already had the Australian national road and time trial titles to its name plus the general classification at the Tour Down Under. The team is yet to win a race this year but Clarke didn't see the first month of the year as disappointing in comparison, explaining that "our team is all about execution. We have a race plan, we ride to the plan and do our best. [Team owner] Gerry Ryan isn't sitting in the background saying, 'you have to win! You have to win!' as long as the processes are executed properly and everyone rider well as a team, that's the important part. If we come second, we come second.
Having finished second at the Cadel Evans Great Ocean Road Race Sunday, Clarke added that the team is riding well and it's only a matter of time before they notch the first win of 2015.
"I think I rode well," he said of the race. "We had Cam and Howson floating around there and helping me out in the closing laps. We didn't have a super quick guy in there end and we made the best of what we had. We more or less rode to the process that was planned and that is all you can ask for."