SAN DIEGO -- How do you know Fernando Tatis Jr. is back? Here’s how:

In the bottom of the first inning of the Padres’ 9-3 loss to the Diamondbacks on Sunday afternoon at Petco Park, right-hander Scott McGough executed the pitch he wanted -- a fastball on the very outside corner of the plate.

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But here’s the thing about Tatis. When he’s truly cooking -- and Tatis is batting .472 in June -- that’s his pitch. That’s his sweet spot. Tatis takes pitches on the outer half of the plate and uses his all-fields power to hit them where few hitters can.

On this occasion, he launched McGough’s fastball a Statcast-projected 410 feet to center field, 109.9 mph off the bat.

“That’s definitely a sign,” Tatis said. “The game speaks for itself. When I’m doing that, I’m definitely doing really good things at the plate.”

Tatis’ 12th homer of the season extended his hitting streak to 15 games -- a career high for Tatis and the longest active mark in baseball. It was little consolation on a day when Adam Mazur was roughed up for eight runs in three-plus innings, as San Diego came away with a split of its four-game series against the reigning NL champions.

The Padres are well aware of the potential playoff implications on this particular matchup. In last year’s standings, one additional victory over Arizona would have flipped the two teams’ seasons. San Diego would’ve reached the postseason. The D-backs would’ve been on the outside looking in.

This year’s NL Wild Card race already looks similar. For now, a weekend split is an acceptable result for the Padres, who, despite falling back below .500 on Sunday, occupy the league’s second Wild Card spot.

In the big picture, Tatis’ revival might be more important than the early June standings, anyway. As Tatis goes, so go the Padres, it often seems. Lately, Tatis has put his early season struggles behind him. How hot is Tatis right now?

“If I touch him -- I'm hurt,” Luis Arraez joked earlier in the weekend. “He's amazing. He looks so special. I'm excited for him, because he started a little slow, but he's a professional, he's an All-Star player. He just needed to keep continuing to play.”

It’s a far cry from where things stood two weeks ago. After his eighth-inning homer in the Padres’ loss to the Yankees on May 25, Tatis chose not to stutter-step around third base. It was the first time he had passed on his signature home-run move since the COVID-shortened 2020 season, which was played in empty stadiums. Asked why afterward, Tatis said simply, “I’m not swaggy right now.”

And he wasn’t. In May, Tatis posted a .725 OPS. That home run against New York was his third and final home run of the month. With his homer on Sunday, he already has equaled that total in June. And, yes, Tatis is stutter-stepping again, so clearly he feels swaggy.

Of course, some of that chatter around Tatis’ struggles was a bit overblown. The underlying numbers -- mainly Tatis’ quality of contact -- indicated he was probably getting unlucky. That luck was bound to change.

But with his numbers suffering -- on May 24, Tatis’ average dropped to .244 and his OPS to .736, a head-scratching number for a player with his level of power -- Tatis vowed not to stay the course. He needed to make better swing decisions.

It wasn’t so much about being passive. It was more about picking the right pitches to do damage with. He spent much of the first two months fussing over his mechanics, when he realized it was a change in approach that he needed.

Two weeks later, Tatis looks like the best version of himself again. Even his outs have been scorched. Over the past two weeks, his 11 barrels are the most in baseball, according to Statcast. So are his 32 hard-hit balls (any ball hit with an exit velocity of 95 mph or harder).

“Now he’s back to: Everything looks really simple for him,” manager Mike Shildt said. “He’s getting balls he can handle. Swing looks great. He’s getting barrel to ball, and the ball’s just jumping off his bat.”

Suddenly, it’s June 9, and Tatis has a slash line of .281/.359/.467. He looks like a surefire All-Star. The biggest thing missing from a mostly solid Padres offense has been the overall power threat. Tatis is helping to change that in a major way.