Back in 2004, Jansen was signed by the Dodgers as an undrafted free agent catcher. Defensively, he had a good reputation as a catcher, due in part to his strong throwing arm. Offensively, his numbers were poor, however. In 2009, the Dodgers convinced Jansen to give pitching a shot. It was a life-changing decision.
Jansen made his debut less than a year later, on July 24, 2010 and has never really looked back. Since switching to pitching, Jansen has become one the the premier relievers of his time, making the last three All Star Games and earning NL Reliever of the Year the last two years.