Martinez, 27, is a career .272/.362/.364 hitter in six Minor League seasons in the San Diego Padres' (2007-11) and Rangers' (2012) systems. Last year for Triple-A Round Rock, Martinez batted .270/.350/.386 in 65 games, and he also appeared in 10 big league games, going 2-for-18. He was selected by the Padres in the 12th round of the 2007 First-Year Player Draft.
The move puts the Orioles' 40-man roster at capacity and gives the organization four catchers: Matt Wieters, Taylor Teagarden, Luis Exposito and Martinez. Martinez, along with all members of the 40-man roster, will be in big league camp.