Pena was released by the Angels at the end of Spring Training and stayed in shape by working out near his home in Orlando. The Rangers signed him to a Minor League deal on June 17, and he went 8-for-24 with a home run in seven games before being called up.
Pena, 36, hit .201 with a .357 slugging percentage in 249 games over the past two seasons with the Rays, Astros and Royals, but he played 1,363 games at first base and won a Gold Glove for his defense, so he gives the Rangers an experienced defender.
"We heard he was swinging the bat well and playing first base the way he plays first base, which is pretty good," manager Ron Washington said. "We just brought in a first baseman that can play first base, and he has presence. He may be a little old, but he has presence. If they throw something in the wrong place, he can hurt you."
From 2007 to 2011, Pena hit .236 with a .505 slugging percentage while averaging 35 home runs and 97 RBIs per season.
"When I first got the call to come back to this organization, I was extremely excited and very grateful," said Pena, who was drafted by the Rangers in the first round of the 1998 First-Year Player Draft and traded to the A's four years later. "I'm just going to do the best I can, enjoy it as much as I can, work as hard as possible and see what happens. This is where it all began, so it's truly special.
"I had faith something would happen, but I didn't want to force it. I wanted to make sure it was the right spot and the right organization. Being patient ... God placed me in the right place. I'm confident this is the right place."
T.R. Sullivan is a reporter for MLB.com Read his blog, Postcards from Elysian Fields and follow him on Twitter @Sullivan_Ranger. This story was not subject to the approval of Major League Baseball or its clubs.