VIERA, Fla. (AP) -- The Washington Nationals filled the last clear-cut need on their roster on the opening day of spring training, acquiring catcher Jose Lobaton and two prospects from the Tampa Bay Rays on Thursday for pitcher Nathan Karns.
Lobaton gives the Nationals insurance behind fellow Venezuelan Wilson Ramos, who has never played in more than 108 games in a season because of various injuries.
''He's a capable backup,'' general manager Mike Rizzo said, ''in case something does happen with Wilson.''
Lobaton, 29, started 76 games for the Rays last season and batted .249 with seven home runs and 32 RBIs. He was expendable because the Rays re-signed catcher Jose Molina and traded for Ryan Hanigan.
Rizzo said Lobaton has above average metrics on defense. A notable exception is a 16 percent success rate throwing out would-be base-stealers.
''We feel that he throws well enough that he should be better than 16 percent,'' Rizzo said.
It speaks volumes about the Nationals' confidence in their talent-laden roster that a move for a backup can fill the last significant hole on the day that pitchers and catchers reported. Barring injury, Rizzo won't be shopping during spring training.
''There's not an obvious spot that we need to address,'' Rizzo said. ''But, as we say, if an opportunity arises, we'll be aggressive and open-minded about it.''
The Nationals are giving up a top prospect in the 26-year-old right-hander Karns, who three made starts in his first taste of the major leagues last season, but they're adding a pair of 22-year-olds from the Jays' pool of talent: outfielder Drew Vettleson and left-handed pitcher Felipe Rivero.
Karns would have been in a crowded race for the No. 5 spot in the rotation. The trade for a younger pitcher alleviates part of that logjam and helps the Nationals stagger their pitching prospects.
To make room for the new players on the 40-man roster, Washington placed right-handed pitcher Erik Davis on the 60-day disabled list with a sprained right elbow.
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