OAKLAND -- The Rangers added to their first-base depth by signing Carlos Pena to a Minor League contract and assigning him to Triple-A Round Rock.

With Prince Fielder out for the season and Mitch Moreland looking at season-ending ankle surgery, the Rangers have been platooning Donnie Murphy and Brad Snyder. Pena, 36, is not expected to be an option at the big league level anytime soon. He hasn't played since being released by the Angels at the end of Spring Training after hitting .139 in the Cactus League.

Pena played with the Astros and the Royals last season, hitting a combined .207 with eight home runs and 25 RBIs in 89 games. He had a .346 slugging percentage.

The Rangers drafted Pena with the 10th overall pick in the 1998 First-Year Player Draft before trading him to the Athletics in 2002. His best years were with Tampa Bay from 2007-10. During that four-year period, he hit .238 but with a .516 slugging percentage and an average of 36 home runs and 101 RBIs. He also won a Gold Glove for his defense.