SAN DIEGO — Seranthony Domínguez spends a lot of his time studying. He studies opposing pitchers and opposing hitters to better understand their quirks. He studies his own team to understand what they do well, and what they don’t, and learn from their mistakes.

After undergoing Tommy John surgery in 2019, the right-handed reliever missed nearly two full big league seasons. He spent those years rehabbing, but he also spent them studying.

He’d pull out his phone and his iPad and he’d turn on his TV. He’d put the Phillies game on one screen, and find two other big league games to put on the others. Part of this was to motivate himself. But most of it was for preparation. He’d keep a close eye on high-leverage spots. If those spots were handled well, he’d take notes. If they were handled poorly, he’d take notes, so that when he did step on a big-league mound again, he’d know how to avoid getting himself in a jam.

Domínguez insists that his mentality hasn’t changed since he debuted as a hard-throwing 23-year-old rookie in 2018. His preparation, on the other hand, has. After a year of rehab, followed by a year of rehab assignments, he feels like he’s seen it all. And because of that, he feels ready for whatever the Phillies might throw at him.

“When I watched these games, I would try to imagine myself there,” he said in Spanish. “Thinking about what I would do to beat the opposing team. Whenever they call my name, I’ll be there.”

Interim manager Rob Thomson wasn’t sure what to expect from Domínguez in his first full season back from that two-year-long hiatus. Some players show short bursts of dominance and then regress. Some re-injure themselves. All of those possibilities entered Thomson’s mind, but 71 games into the season, his concerns have vanished like a fadeaway pitch.

“The stuff is just getting better and better,” Thomson said. “The velocity is jumping up. The sink is better, the cut is better, his arm is getting stronger. He looks like he hasn’t missed a beat.”

In a bullpen full of unwelcome adventures, Domínguez is a rarity. He is someone Thomson wholeheartedly trusts, and for good reason. In 2022, Domínguez has a 1.69 ERA in 28 appearances with 35 strikeouts. The 101 batters he’s faced thus far have hit .172. Right-handers have had even less luck: they’re batting .123 and striking out in 40% of their plate appearances.

He has already helped the Phillies plenty, but in these last 91 games, Domínguez will be asked to do more. Corey Knebel, who signed a one-year, $10 million deal to be the Phillies closer this season, has struggled with his command. He’s been moved into lower leverage spots, which opens up the ninth inning to whomever is trustworthy enough to take it.

Domínguez is the obvious frontrunner. Thomson has yet to name him as the closer, but he has said there are few lineups he wouldn’t trust the right-handed reliever to face. The reason is simple.

“He’s fearless,” Thomson said. “I don’t think there’s a situation that’s too big for him, and I don’t think there’s a hitter that’s too big for him. He goes out there and says, ‘This is my stuff. Go ahead. Try to hit it.’”

Most of Domínguez’s closing experience came in 2018. In 24 opportunities, he has saved 16 games. For his career, he has a 3.32 ERA in 58 hold or save situations with 76 strikeouts — a figure that seems a bit high given the dominance Domínguez has shown this season. But four years later, he feels more prepared for the role.

“I think I’d like to be [the closer] if I was asked to be, if I had the opportunity to be,” he said. “It’s a very important job. I’m ready to do whatever I’m asked to do to help.”

Thomson says that part of what makes Domínguez great is that he doesn’t take his stuff for granted. He cares about his craft. He is a perfectionist. Once or twice a week, the reliever will throw flat grounds. He’ll only go about 10 or 15 pitches, but he will scrutinize every pitch. If his slider is released too high, he’ll curse. If a sinker bounces before it reaches the catcher’s mitt, he’ll slap his leg with his glove. If a fastball doesn’t come out of his hand the way he’d like it to, he’ll let out a long, heavy breath. And then he’ll throw more pitches — as many pitches as it takes to feel like he’s gotten it right.

For Domínguez, it’s all in the preparation, and the preparation has to be perfect. If the preparation is perfect, then he can go on the mound and not think about being perfect. He can just be himself. Which, for the Phillies, is more than good enough.

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