They were teammates with the Reds for more than two years. Lopez said Pena needs a change of scenery. Pena found himself on the bench for most of this season and was hitting .218 with five home runs and 17 RBIs with the Red Sox.
"Like anything, if you don't play, your timing is messed up," Lopez said. "I've been there. I've experienced it. It's not easy at all."
Lopez said Pena will not have any problems hitting home runs at spacious Robert F. Kennedy Stadium and should be more relaxed with the Nationals. Pena's power is often compared to some of the great home run hitters of today and yesterday. In fact, Lopez went so far as to say that Pena will have tape-measure home runs similar to what Frank Howard did in the late 1960s and early '70s.
"I think it's good for him to come back to the National League. There are too many offspeed pitches in the American League. I think he will do better here. He will help the team out more," Lopez said. "There is way less pressure here than in Boston; he will find his way here. It will be good to have someone where the ballpark doesn't matter to them."
Injury report: Right-hander John Patterson (sore right elbow and forearm) will throw live batting practice at the team's Spring Training complex in Viera, Fla., on Sunday. The Nationals are hoping that Patterson will pitch in a Major League game sometime in September.
Stat of the day: The Nationals are 2-39 when they score three runs or fewer.
Did you know? The Nationals have six players -- Pena, Lopez, D'Angelo Jimenez, Austin Kearns, Ray King and Dmitri Young -- on the 25-man roster who played in the Reds organization.
Coming up: The Nationals play the second game of a three-game series against the Mets on Saturday night at 7:05 ET. Washington left-hander John Lannan will face New York left-hander Oliver Perez.
Bill Ladson is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.