SAN FRANCISCO >> Aptos native Jared Koenig, a 31-year-old pitcher in his second season with the Milwaukee Brewers and third in MLB, hasn’t yet kicked up his cleats.

Though the 6-foot-5, 245-pound left-hander established as one of the top arms in the Brewers’ bullpen — he was named the team’s “Unsung Hero” by the Milwaukee Chapter of the Baseball Writers Association of America last season — he knows that he works in a what-have-you-done-for-me-lately business.

Sure, Koenig was more than elated to hang with his parents, Greg and Cecilia, and get a surprise visit San Francisco Giants television and radio broadcaster Mike Krukow before the Brewers’ game at Oracle Park on Monday, but he was also getting mentally prepared for the task at hand after participating in team meetings and pre-game warmups.

“I’m just trying to go out and do my job, and if I do that, then I’m happy,” Koenig said. “It’s one day at a time, one pitch at a time, I can’t look too far ahead, I kind of just got to focus on the day.”

Koenig is excited to still be checking off “firsts” in his relatively new MLB career. He made his first appearance in his return to the Bay Area on Monday, but he didn’t have the outing he’d hoped for. The middle reliever gave up two hits and one run in two-thirds of an inning when manager Pat Murphy elected to make a pitching change during his team’s 5-2 loss.

Good days and bad days. Such is the life of a pro baseball player. Koenig knows the number of good days have to be the norm.

After making his MLB debut with the Oakland A’s in ’22 and spending the entire ’23 season as a minor leaguer in the San Diego Padres’ organization, Koenig took his game to another level in last season. He started, pitched middle relief and received late innings work for the Brewers. He posted a 9-4 record with a 2.47 ERA and 1.24 WHIP. In 62 innings of work, he gave up 54 hits, 17 earned runs, 23 walks and struck out 63.

He has already made 12 appearances through 24 games after making 55 a year ago.

Koenig hasn’t yet started a game after making six starts a year ago, but he’s ready for whatever role the Brewers throw his way.

“Last year, I’ve pitched in innings one through 11, so it’s kind of a nice thing to say,” Koenig said. “I don’t know how many other guys did that last year. But it’s just cool to kind of continue and if they need to be me to be the, like, Swiss Army knife, then I can do that.”

Pitchers are constantly fine-tuning their arsenal in an attempt to keep hitters off-balance, making weak or no contact. Koenig — who pitched at three colleges, and in five independent leagues, plus a professional stint in Australia before signing with the A’s — is trying to build upon his ’24 showing and get the Brewers back into the playoffs.

“Last year, he was clutch as anybody in terms of, he’d have maybe not his best stuff, hang in there, 30-plus pitch inning, and still get out of it,” Murphy said. “He just had a knack for making the big pitch. And he’s emerged now into our highest leverage pitcher. We trust him, we believe in him. He’s got a great story in that it took a while to establish himself, but he is alive and well and doing well.”

Koenig is out to be the best version of himself. He’s constantly striving to improve his craft, which is why he calls his personal trainer, Matt Rossignol, of Rossy’s Training in Scotts Valley, near daily.

Koenig said his biggest growth as a pitcher has come under Rossignol. Which is why the two have spent a good chunk of each offseason together since 2018, working on ways to make Koenig fundamentally sound and harder to hit that ever.

“I’m still growing,” Koenig said. “There’s still things to improve on. Every year I’m training there, no matter what.”

After completing college, Koenig’s fastball was still stuck in the mid 80-mph range. Now, he sits at 95 and above. All his pitches have gotten nastier, more effective.

Rossignol said two attributes have helped Koenig find success: He’s not only uber competitive, and has a drive to succeed, he has the ability to take lessons during training and apply them almost immediately. Those traits are also two of the reasons the two chat so frequently during the season.

To the common eye, Koenig has been an overnight success. Only a select few have seen the work Koenig puts in over the offseason. He’s at Rossy’s six days a week, three to five hours a day.

“It doesn’t just happen,” said Rossignol, a former independent league pitcher. “It took hard work.”

Despite a shaky outing Monday, Murphy won’t hesitate to bring in Koenig for the Brewers’ next high-leverage situation.

“He gets every big situation,” his manager said. “He gets everybody’s middle of the order.”

Rossignol believes Koenig’s story is just starting.

“To get get released by two independent leagues, pitch in four to five indy leagues and still believe in yourself is a huge testament to him,” Rossignol said. “I’ll never doubt that guy.”

Koenig is feeling comfortable in the Brewers’ clubhouse and confident on the mound, but don’t ever expect him to ever kick up his cleats. Arriving to the bigs is only a portion of the challenge. Staying is another.

“You never can kick the heels up, especially at my age,” Koenig said. “I’ve got to keep it going.”