"We believe John fits well into our catching situation," Padres general manager Josh Byrnes said. "As a left-handed hitter with a good history of getting on base, he will provide us with depth and will help balance the roster from a left-right perspective."
Baker missed all but 16 games in 2011 after undergoing surgery on his right elbow in the offseason. He is a career .271 hitter with 14 homers, 42 doubles and 89 RBI in 212 games over the last four seasons with the Marlins.
LeBlanc went 5-6 with a 4.63 earned run average in 14 starts for San Diego last season. The 27-year-old Alabama product was 17-22 with a 4.54 ERA in 54 games (52 starts) with the Padres since 2008.