ST. PETERSBURG -- Carlos Pena wasn't supposed to be on the team.

The Rays first baseman was a roster casualty on the final cut of Spring Training. Then, Greg Norton had surgery to his right knee, and Pena was brought back almost before he could even leave.

Now, with Akinori Iwamura on the disabled list with a right oblique strain, Pena is getting most of the starts at first base. If anything, his story is one of perseverance.

"I keep on saying this, and I honestly mean this, I'm so grateful to be here," Pena said. "I don't take anything for granted. I never have. To come here every single day and put on the uniform, it's a privilege and I make sure I remind myself about that every single day. So when I come to the park, I'm going to bust my tail every single day. It's easy to do that because I feel it's such a privilege to put this on."

Rays manager Joe Maddon said he was curious about Pena when the team signed him.

"From a distance, I've always thought he has a lot of ability," Maddon said. "The biggest thing I've tried to convince him about this spring is to get him out of this [pull-hitting] mode."

Pena's homer Thursday against the Angels went to right-center field, but he has hit some of his four home runs to the opposite field.

"I think if we keep him hitting to the opposite side of the field, I think we can see him hit as good as he's capable, which might be .270, .280," Maddon said. "I find him fascinating. ... This may be [the right situation for Pena]. I think Carlos has the potential to do that."

Maddon called Pena the kind of guy the Rays need in the clubhouse.

"We need young professionals in our group," Maddon said. "Guys that are 'force multipliers'. We've talked about that. Colon Powell mentioned that years ago. He talked about people who are 'force multipliers'. Those are the kind of guys you want, guys who make the people around them better. That's what we're looking for. And I think he's one of those guys."

Pena spoke about the difference in being in the lineup everyday compared to coming off the bench.

"I expect to be in the lineup every single day," Pena said. "And if I get to the park and I'm not in the lineup, I'm going to cheer my teammates on. I don't take anything for granted. If I'm not in there, what do I have to do? I have to support my teammates, [and] do my part to make sure they're ready.

"I think that's the kind of attitude we're trying to grow here, and it goes a long way. I think we have a really tight team. We have good chemistry. That's why we've been playing pretty good baseball, even though the record doesn't show it. I really believe we're playing really well."

Harris more selective: Brendan Harris has taken over as the team's starting shortstop, even if Maddon has not made a proclamation asserting that fact. Among the things Harris has done to impress his manager are the number of pitches he has seen per plate appearance.

"It's way up there," Maddon said. "Coming out of Spring Training, he was like a two- or three-pitch at-bat. Now, I think he's [averaging] like 4.7. He's one of the higher pitches-per-plate-appearance guys on our team. And I love the way he's working an at-bat."

Harris said working at-bats and being aggressive is "kind of a battle sometimes."

"You want to be aggressive, so you don't want to let a couple of pitches go," Harris said. "But if I see one [pitch], I get more comfortable. I might see the pitcher's pattern a little bit more. So maybe not trying to get five- or six-pitch at-bats, but I want to see at least two pitches. It kind of gets down to a confidence thing where even if he has strike one or strike two, you feel like you can still do something."

Maddon has called Harris "a Tampa Bay kind of player" and was asked how he defined that.

"He plays it hard-nosed every play," Maddon said. "I think he puts the team ahead of himself. He totally cares about winning first. He's the kind of guy who supports others when he's not playing. And during the course of the game I think he's able to think on his feet during the game. He's aware of his situation. He has an awareness about him."

Up next: The Rays play the Twins on Wednesday in the second game of their three-game series in a 7:10 p.m. ET contest. Right-hander Jae Seo will start for the Rays and will be opposed by right-hander Boof Bonser.