Vuelta a Alemania
He joined the ProTeam in 2008, signing his first contract as a professional. His first notable result was a 6th position in the final classification of the 2008 Vuelta a Castilla y León. He made his ProTour debut in the Tour de Romandie, but did not finish the race due to a fall, which resulted in a fractured collarbone. He fully returned in top shape in the Deutschland Tour, in which he started as Rabobank's team leader, eventually finishing 7th in the overall general classification. After a disappointing spring in 2009, the season was over for Mollema due to infectious mononucleosis (Pfeiffer's disease).