The nine-day Tour de Suisse starts on Saturday with a 9.4km time trial in Bellinzona and also sees Fabian Cancellara (Trek Factory Racing), world champion Rui Costa (Lampre-Merida) and Mark Cavendish (Omega Pharma-QuickStep) in action as they prepare for the rapidly approaching Tour de France.
Instead of racing in recent weeks, Sagan has spent a long spell training at altitude near Colorado before returning to Europe. The Tour de Suisse will be his final preparation race for the Tour de France, where he will target further stage victories and a third consecutive green points jersey.
"I feel good and ready to be back in competition," Sagan said in a statement from the Cannondale team.
"I know how hard and important the next months will be, and this is why I chose to stay in the US to recharge my batteries. I needed a few weeks for specific training and to relax my mind. But now it's time to focus on the races and I'm really motivated."
"Every year becomes more challenging for me, but my goals are still the same. In Switzerland, it will be important to have good feeling and to take good results. In France, I'll chase the green jersey and stage wins. Between these two events I'll race the national championship, another important race in my schedule."
Sagan has always used the Tour de Suisse to prepare for the Tour de France, winning stages along the way. He took two stage wins in 2011, four in 2012 and two in 2013.
"I always considered the Tour de Suisse as one of the most indicative tests in view of the Tour de France," he said.
"The race includes many mixed stages with routes suited for my characteristics. This is the best way to push hard and to see how my legs reply. Of course I like to win, and this is also the best way to gain confidence. I'll try to follow the same steps this year - I'll see day-by-day which are the best chances."