OAKLAND -- There was no margin for error for Mariners at the cavernous Coliseum on Wednesday, literally and figuratively, which allowed one defensive miscue to loom large in a 2-1 loss to the last-place A’s.

That error was the latest, and perhaps the most frustrating, for Jesse Winker in what’s been a disappointing first season in Seattle.

On Vimael Machín's slicing line-drive into the corner in the seventh inning, the left fielder made contact with the ball but watched it go through his legs and dribble under the wall’s padding in fair territory. Running from first base, Oakland’s Jordan Diaz got the green light rounding third. Winker’s throw then missed cutoff man J.P. Crawford, who was in shallow left, and instead hit Adam Frazier, who ran all the way from second base then had to throw across his body to the plate.

But by that point, Diaz -- a below-average runner -- had slid past Mariners catcher Cal Raleigh to put Oakland ahead for good.

"I missed the ball," Winker said. "That’s really all I got. I just missed it. I wasn’t expecting that. It just took a weird hop and I missed it."

That sequence broke a scoreless tie, but it wasn't the A's only run in the inning charged to reliever Erik Swanson, who walked Diaz on four pitches before surrendering the double. That frame was enough to prevent Luis Torrens’ pinch-hit solo homer in the eighth from having any impact on the outcome.

"It’s not a difficult play," Mariners manager Scott Servais said. "The ball is off the wall -- catch it and get it in. He wasn’t able to do that. It’s something that we’ll continue to look at. Jesse has played for a really long time and it’s been a struggle for him recently."

The error was a glaring microcosm of where both Winker and the Mariners are with just 14 games remaining and their chances of hosting the Wild Card Series creeping away. Seattle’s grip on the final AL Wild Card spot is four games over Baltimore (plus a tiebreaker), but the club is now 2 1/2 games back of Toronto for the top spot, which it shared with the Blue Jays before this 1-5 road trip began.

Struggles against teams out of contention would exacerbate any contending team’s frustrations. Yet, even if the Mariners were undefeated on this road trip, it wouldn’t change the reality that every out in October will be vital and the chance to overcome fielding errors, slim. Winker ranks last among MLB outfielders with -15 defensive runs saved and has been worth -9 outs above average, per Statcast.

Asked where Winker stands defensively within the Mariners’ roster construction moving forward, Servais said: "I think we know where we’re at. We’ve got to get better."

The Mariners have substituted Winker late in games 12 times in the past month, but only with a lead -- the logic being that his .338 on-base percentage, aided by 80 walks, makes him a potential run-scorer.

"With where we’re at in the season, we have made defensive replacements late in games when we do have a lead," Servais said. “It was a 0-0 game there late. That's a play that typically should be made."

Winker also recognized that his challenges have been costly.

"Obviously I want to help the team win," Winker said. "That's why I'm here. But sometimes you don't. And as much as that is a tough pill to swallow, it's the reality of this game. It's not fun when you're not helping the team win. It's not enjoyable at all."

After an All-Star season in 2021 with Cincinnati, production that prompted the Mariners to acquire him in a Spring Training blockbuster along with Eugenio Suárez, Winker is hitting .216/.338/.339 (.677 OPS) this season. His 217-point dip in slugging percentage from ‘21 is MLB’s second-largest drop among 168 qualified hitters. After going 0-for-3 on Tuesday, he hasn’t had an RBI since Aug. 19 and has more walks (12) than hits (10) in that stretch.

"This isn't what I come to the field to perform like," Winker said. "I want to help the team win. And as of late, I really haven't been. You just keep running back out there. I believe in myself. It's not a lack of belief, but it's just sometimes these things string together."

Earlier Wednesday, the Mariners recalled Jarred Kelenic from Triple-A Tacoma, another left-handed-hitting outfielder who’s also still looking to find his footing in the Majors this season. Kelenic, the better defender, probably would’ve subbed for Winker if Seattle had a late lead -- and will potentially get more games in left field moving forward.

"You don't eliminate the past. I'm not running from it," Winker said. "It is what it is. It's the reality of the sport, the reality of this job. It can happen to you in any year. Obviously, you'd prefer for it not to happen in the middle of a playoff push for a team that hasn't been in the playoffs in a minute, but it happens. You just come back tomorrow. And when it's your turn to play, you play."