Peña struck out Alex Blandino and yielded an infield single to Mark Payton to open the fifth, but Peña appeared to be in discomfort after his first pitch to Kyle Holder.
After a brief mound meeting with the team athletic trainer and manager Joe Maddon, Peña gingerly walked off the field on his own.
Maddon said that the pain was in the hamstring area, but he did not know much more about the extent when addressing reporters after the game.
“He just felt the tightness. But that's one of those things; he’s got to go through the steps,” Maddon said. “It could have been a cramp, I don't know. So I'm just going to wait 'till I get back and he's had a chance to be observed properly and then we'll figure it out.”
Peña, 31, is expected to give the Angels a multi-inning option out of the bullpen this season. He appeared in 25 games in 2020, posting a 4.05 ERA across 26 2/3 innings.
In other health-related news, outfielder Justin Upton was scratched from Monday’s game due to a non-COVID related illness, according to the Angels.
Maddon said that Upton looked fine earlier in the morning and through the workout, but felt ill later, closer to game time.
“He looked good. I was down there watching him. I talked to him and I think when he came upstairs, he didn't feel right,” Maddon said. “And that's when we shut it down. He was well in the morning. He participated in practice and then didn’t feel great coming upstairs.”
It was Adell’s second homer of the spring.
“There's no part of the ballpark that can hold him,” Maddon said. “I like when he stays in the middle, I like when he's gap-to-gap. It doesn’t have to be pulled for the ball to go far.”