SEATTLE -- Baseball has shown time and time again how missed opportunities can come back to haunt a team. In the case of the A’s on Friday night, it only took a matter of minutes for that statement to hold true.

Fighting their way back from an early three-run deficit against the Mariners, the A’s failed to capitalize on a bases-loaded opportunity in the top of the seventh, keeping the game tied. Shortly after in the bottom half of the inning, Dylan Moore manufactured a go-ahead run that was aided by a pair of wild pitches by left-hander Jake Diekman and Seattle never looked back as it topped the A’s, 4-3, at T-Mobile Park.

With Houston winning earlier in the day, Friday’s loss dropped the A’s back to 3 1/2 games back of first place in the American League West.

Diekman, who has been a key part of a resurgent A’s bullpen over the past couple of weeks, first allowed Moore to reach base on an infield single with two outs. Moore stole second base, then took third on Diekman’s first wild pitch before later scoring on the second. Both errant pitches came on sliders low in the zone to Shed Long Jr. that rolled past catcher Sean Murphy.

“Just some balls in the dirt,” A’s manager Bob Melvin said. “With sliders, he’s trying not to hang them and make too good of pitches. They ended up being some tough blocks that are in between where you get a decent hop and where you don’t. They just bounced off Murph.”

Also throwing a third wild pitch that allowed Long to take second base, the rough inning marked the first time Diekman had ever thrown three wild pitches in one game over his 10-year Major League career. He’d only thrown multiple wild pitches once prior, uncorking two on Aug. 25, 2018, while a member of the D-backs in a game also against the Mariners.

It was a tough spot for Diekman, one that all of his teammates can empathize with, whether hitter or pitcher.

“Tonight, he was a little off,” A’s left fielder Mark Canha said of Diekman. “As an athlete and teammate, you fully understand that you’re going to have nights like that. That’s part of baseball. Everybody’s been there. 

“We slipped a little. I think a good teammate looks at that and says, ‘All right, we move on.’ We continue to have confidence in him and keep going, because Jake is nasty. He’s been so good for us this year and he’ll be good the next time.”

The late-inning stumble overshadowed what turned out to be a rather impressive outing for Frankie Montas.

Save for a mini lapse in which he allowed three runs on back-to-back homers in the second on sinking fastballs left in the middle of the zone, Montas was dominant through most of his start. The right-hander racked up 10 strikeouts across six innings while allowing three runs on four hits.

The splitter has been a pitch that makes Montas look elite when he throws it often. Before allowing the back-to-back homers to Cal Raleigh and Luis Torrens in the second, Montas had only thrown the split three times. After that sequence, he made it a point to throw the pitch more often. Montas allowed just two hits the rest of the way, ending up throwing the splitter for 33 of his 102 pitches, the most of any of his four pitches.

“There were two pitches I totally missed my spot,” Montas said. “I was yanking my fastball. I feel like my splitter made it better. That makes the fastball better later on.”

The A’s offense picked up Montas by climbing back into the game with a pair of solo homers by the two Matts -- Chapman and Olson -- in the third and fourth inning off Mariners starter Yusei Kikuchi. For Olson, the homer was his 26th of the year, which ranks second-most among American League first basemen.

Mark Canha tied it up in the fifth with a clutch two-out double off Kikuchi that scored Jacob Wilson from first, but that marked the end of the A's offensive output on the night.

Though Diekman’s slipup in the seventh was a rarity, the A’s struggles with situational hitting have carried throughout the season, which could lead to a more aggressive pursuit of a middle-of-the-order type hitter with the July 30 Trade Deadline now less than a week away.

The strikeout of Elvis Andrus with the bases loaded in the seventh marked the second straight day in which the A’s were unable to score in a bases-loaded situation. For the season, Oakland’s offense entered the night batting .224 with the bases loaded, which ranked second-lowest in the American League.

“That’s a difficult situation,” Canha said of the bases-loaded struggles. “Everything is amplified a little bit. You get a lot more breaking stuff and pitches on the inner half of the strike zone. You get a guy’s best stuff in those situations, and it’s difficult to stay within yourself and be present in those at-bats. 

“I guess, if you’re asking those questions, it means we need to do better.”