Martinez, 26, was the Padres' 12th round draft pick in the 2007 draft. His contract was purchased in November, 2010, and he was optioned last season, so he has two options remaining.
|162 Game Avg.||162||501||434||52||88||7||7||7||74||59||103||.203||.309||.305||.614||76|
Kelly is a 24 year old righthander who the Rangers acquired from Oakland last winter in exchange for Guillermo Moscoso. Kelly is a fringey arm in an organization loaded with fringey arms, and he probably didn't have much of a future here in Texas. I'm sure that, given the Padres' track record with these sorts of guys, he'll end up posting an ERA in the 1s in middle relief for San Diego in a few years.
Acquiring Martinez puts the Rangers' 40 man roster at 37 players, and he effectively replaces Taylor Teagarden as the team's third catcher, the guy who can bounce up and down between AAA and the majors as circumstances and roster needs dictate. The fact that he has a pair of options remaining is crucial here, since it allows the Rangers more roster flexibility than a player who would have to clear waivers to be sent down would give them.