ST. PETERSBURG -- A month ago, Taj Bradley looked untouchable. He dominated July and was rewarded appropriately, as he was named American League Pitcher of the Month.

August was not so kind to the 23-year-old right-hander, and it saved its toughest blow for last.

“The month of August has been kicking my ass, for sure,” Bradley said after giving up eight runs while recording only seven outs in the Rays’ 13-5 loss to the Padres on Friday night at Tropicana Field. “I’m just taking it like Rocky, wearing it, and hopefully I’ll throw a punch back sooner or later. That’s what I’m waiting on.”

After allowing a season-high-tying 13 runs and eight walks, Tampa Bay fell back to two games below .500, at 66-68, and seven games out of the final AL Wild Card spot.

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The Rays believe Bradley will start landing counterpunches eventually. He was simply too good for too long earlier this season, although that stretch is moving further in the rear-view mirror.

With six scoreless innings in Toronto on July 25, Bradley capped a nine-start run in which he was arguably better than any pitcher in baseball. He went 5-1 with a 0.82 ERA during that time, never pitching fewer than five innings or allowing more than two runs. He looked the part of an ace.

Since then, Bradley has gone 0-5 with a 9.85 ERA in six starts and seen his ERA jump nearly two runs from 2.43 to 4.35. Friday night was the shortest start of his young career and arguably his roughest performance since the nine-run, 10-out outing in Baltimore on June 1 that seemingly turned his season around for the better.

It was a tough night from the start for Bradley, coming off back-to-back six-inning performances in Oakland and Los Angeles. The Padres put 13 balls in play against him, and 10 qualified as hard hit, with an exit velocity of 95 mph or greater. He gave up eight hits and two walks and only struck out two batters, and he needed 71 pitches to complete 2 1/3 innings.

“They did exactly what they were supposed to do. They hit the mistakes and they took the good pitches,” catcher Alex Jackson said. “It's pretty straightforward, honestly.”

Bradley fell behind in the first inning on three singles, a sacrifice fly and another run-scoring hit by Jackson Merrill. He gave up another run on two singles and a walk in the second, then Manny Machado delivered San Diego’s biggest hit of the night, blasting an 0-1 fastball near the top of the zone out to center field for a three-run homer.

Five of the Padres’ seven hits in the first two innings came against Bradley’s splitter, the offspeed pitch that helped him baffle hitters during his hot streak. That pitch has dropped less over his past six starts than during his first 14 outings, according to Statcast data, and opponents have had a lot more success as a result.

Manager Kevin Cash noted that the Rays are “not seeing the depth that he’s capable of creating” on Bradley’s splitter. But he and Bradley also credited San Diego’s lineup, which leads the Majors in batting average, for spoiling splitters outside the strike zone and smacking the ones in the zone.

“I just love the fact that we saw [the splitter] good. Guys weren't trying to do too much,” Padres manager Mike Shildt said. “We were making him get it in the zone. ... We were just patient, looking to get good pitches to hit.”

The Rays scored four runs in the second on a two-run single by Taylor Walls and a two-run homer by Yandy Díaz, who exited in the fourth due to left knee patellar tendinitis. Despite totaling 10 hits and six walks, the Rays only managed to score one more run while racking up double-digit strikeouts (13) for the 10th time in their last 14 games.

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“Our offense needed an inning of swinging the bats like that. We got some hits throughout the game,” Cash said. “Got to do a little bit more.”

Bradley surrendered another single and a walk in the third. After striking out the first batter he faced, reliever Erasmo Ramírez fell behind Jurickson Profar, 2-0, before the Rays elected to intentionally walk him to load the bases with two outs. It looked like a smart decision when Ramírez got ahead of Donovan Solano, 0-2, but he promptly threw four straight balls to walk in another run then gave up a two-run homer to David Peralta in the fourth.

“Load the bases, you’ve got options at three different spots to get outs and trust Erasmo in that moment that he’s going to make some pitches,” Cash said. “It started off right, then we just couldn’t put him away.”