SEATTLE -- When the A’s arrived to Mesa, Arizona back in February for Spring Training, they envisioned their forthcoming season as one in which they would finally break through for a deep playoff run.

It only seemed like a logical next step. After all, these A’s had already reached the postseason for three straight seasons, and were fresh off an appearance in the American League Division Series in 2020.

Those lofty expectations, World Series aspirations and all, won’t be realized in 2021. Those slim hopes the A’s fought desperately to grasp onto entering the final week of the regular season dissolved completely following a 4-2 loss to the Mariners on Wednesday at T-Mobile Park. With three games left in the regular season, Oakland is officially eliminated from postseason contention, now 4 1/2 games back of Boston in the race for the second American League Wild Card spot.

“It’s a massive disappointment,” said A’s starting pitcher Chris Bassitt. “No doubt about it. We expected to compete for a World Series and we fell way short.”

First up on the A’s list of goals this season was to defend their AL West title. But after trailing the Astros in second place for most of the year, the primary focus over the last month shifted to earning one of the two Wild Card spots up for grabs.

The A’s figured they’d have to battle AL East clubs like the Red Sox, Blue Jays and Yankees for those spots. Never did they think the Mariners, whom they consistently sat above in the AL West standings until the past two weeks, would overtake them. Yet here they are, with Wednesday’s defeat marking the A’s 12th consecutive loss against Seattle. It’s their longest losing streak against any team since dropping 12 straight to the Angels from Sept. 18, 1996-Sept. 17, 1997.

Over the last 10 games, the A’s have gone 3-7. All seven of those losses have come against the Mariners.

“They’re good,” A’s outfielder Mark Canha said. “They do everything. They kind of remind me of us. They scrap and do a lot of things well. They fight all nine innings. You gotta give them credit. We’re a good club and they beat us regularly.  They outplayed us. It felt like every time we played them that we would hang around and at the end they were just a little better.”

There are a myriad of deficiencies you can point to when dissecting what went wrong for the A’s. Losing a spirited team leader in Ramón Laureano to suspension. The loss of their All-Star ace in Bassitt at a pivotal point in the season to a devastating injury. A bullpen that frequently failed to hold close leads late in games, especially down the final stretch. The downfall was collective.

“It’s not like one individual let us down,” said A’s third baseman Matt Chapman. “We just came up short. For me, personally, I’m very upset with how I finished this season. I know I’m capable of more. It just hurts when I feel like I could have done more to help this team.”

The power returned for Chapman, who was returning this year from offseason hip surgery. But while he’s closing in on 30 home runs, the rest of his offensive game took a step back from what was All-Star level in 2019. On Wednesday, he became part of dubious A’s history, becoming the first player in franchise history to strike out 200 times in a single season.

“When I am playing at the level that I usually do, I can help this team win more baseball games,” Chapman said. “I’m just going to use this as motivation to get to work in the offseason. Finishing this poorly, personally, makes me hungry. I want to come back and come back stronger to help this team reach the postseason and more.”

The manner in which the A’s went about the second half was also a surprise. Going on amazing second-half runs has been their trademark. From 2018-20, their combined record in the second half was 104-61. After this year’s All-Star break, though, the A’s have gone 33-34.

“We just didn’t have that magic at the end of the year that we usually have,” Canha said. “That’s usually our calling card. We come back and win those games. Historically, we’ve been good at doing that. We just didn’t have it this year.”

Without question, his year was a step back. Things will get more uncertain this offseason with several key players set to hit free agency, Canha included. However, these A’s remain optimistic that their window for making a World Series run isn’t closing just yet.

“We’re only a few wins away from being in it,” Chapman said. “I put a lot of that blame on myself for not playing as well as I should have. But I still believe in this team. I still believe that we have a lot of guys that are very talented and capable returning that, with the right additions, we can be a great team still.”