"He's swinging the bat well and playing first base the way he plays first base and that's pretty good," Rangers manager Ron Washington said. "Think we just brought in a first baseman that can play first base and he has a presence. He may be a little older but he has presence. If you throw something in the wrong spot, he's going to hurt you. He knows how to play around that bag (and) his presence is important."
Pena will bat sixth and play first base against the Detroit Tigers.
"I was training and just staying ready," Pena said. "I had faith that something was going to happen. At the same time I didn't want to force it and I wanted to make sure it was right."