Mason Miller started his career with the A’s, where it took him just a year and a half to establish himself as one of baseball’s best relievers. But when he was traded to the Padres at last year’s deadline, the Slim Reaper hit another gear, and not just because he set a playoff record with a 104.5-MPH fastball that set the baseball world (and social media) ablaze.

In September and October, opposing hitters went an absurd 1-for-37 with 26 strikeouts against him. So, what changed? As Miller tells it, there are two main things.

“Pitching in front of these fans is a big part of that,” Miller said.

Miller never had big crowds in Oakland or Sacramento. Getting 40,000 a night at Petco Park tapped into his ultra-competitive side. The other element is getting to work with Padres pitching coach Ruben Niebla.

“Ruben’s special, man,” Miller said. “And a lot of that comes from not only him but also the team that he’s assembled and how they work together. The willingness to have constructive conversations — you know, there’s no egos here. This is all just about: How can we be the best staff that we can be, and how can we help this team the most that we can?”

During the offseason, there were talks about Miller stretching out to be a starting pitcher again. However, those discussions didn’t go very far.

“It’s a fun idea to talk about, but we would be moving away from something that I’ve proven to be very successful at and have the ability to stay healthy in, which is the big reason that I ended up doing that in the first place,” said Miller, who began his career as a starter but was moved to the bullpen after dealing with an elbow issue. “At this point, I think that makes the best sense, not only for myself but also for the things I’m going to be able to do for the team.”

You’ll hear Miller talk about the team a lot. Part of the reason he embraces the high-stress world of MLB closer is his desire to finish what his buddies have started.

“Just the chance to bring guys into the locker room with a win — we show up at 1 in the afternoon and everything that we do that day is designed to put us in the best chance to win that game,” Miller said. “So, all that work that’s gone into the day to that point, and we’re in we’re in a chance to win a game, and I’m the guy we turn to. I take that to heart. It really means a lot to me to be that guy. I just want to do my part for the guys.”

Miller’s teammates are quick to praise him for his team-first attitude. They also don’t mind having a front-row seat to see the hardest thrower in the game.

“Watching him from afar, we could always tell, obviously, the talent and everything is there,” said second baseman Jake Cronenworth. “But to watch it in person and to see how he works day to day, and how he shows up to the field, is just as impressive. I’m super excited to see what he can do with a full year with us.”

“He’s incredible,” said center fielder Jackson Merrill. “And Mason is the man, too — a super nice guy. He’s electric. He’s an even better person off the field too. I’m just excited he’s on our team and nobody else’s.”

Well, Miller will be joining one other team: He’ll take a little break from the Padres in March because he’s earned the honor of being the closer for Team USA in the upcoming World Baseball Classic. When he was asked if he’d be interested in donning the Stars and Stripes, it was an easy yes.

“I think it’s an opportunity that I didn’t feel like I could pass up,” Miller said. “This could be a once-in-a-lifetime, once-in-a-career chance, to put on those colors, put on the USA uniform. That’s something I’m really honored to do.”

San Diego is used to having elite closers. Over the years we’ve been spoiled by the likes of Goose Gossage, Rollie Fingers, Mark Davis, Trevor Hoffman, Heath Bell, Huston Street, Kirby Yates, Brad Hand, Mark Melancon, Josh Hader and Robert Suarez. All of them were All-Stars and three are in the Hall of Fame (Gossage, Fingers and Hoffy). As wild as this sounds, Miller could end up being the most dominant one of all.

New Padres manager Craig Stammen was a relief pitcher himself. So, how’s he feel knowing he can hand the ball to Miller in the ninth inning?

“I feel pretty good about that one,” Stammen said.

There’s no doubt the Friar Faithful feel the exact same way.