SEATTLE -- Of course it was another one-run game. This critical series within this critical homestand has been full of them, and no team in the Majors has been better in such circumstances than the Mariners, who after Sunday’s 4-3 victory over the A's are just 1 1/2 games out of a postseason spot.

With the win, the Mariners advanced to a season-high eight games above .500 (54-46) and are now 8-1-2 in their past 11 series. Furthermore, they advanced to 6-4 this season against the division-rival A’s, who sit directly ahead of them and currently occupy the second American League Wild Card.

The Mariners will now welcome first-place Houston to T-Mobile Park for three games, leading them into Friday’s Trade Deadline -- which figures to come with plenty of intrigue now that all of a sudden, as winners of nine of its past 13, Seattle seems like a strong bet to buy.

“You want [the front office] to feel like we're doing a good job and that this is a thing to go for,” said Kyle Seager, who had a two-run single as part of a decisive four-run third inning against A’s starter Cole Irvin. “I think it's been preached, this rebuild, so much. But I mean we're right there on the edge of this thing. So, certainly, you would like to have them make moves and get the team as good as we possibly can.”

This is Seager’s 11th -- and quite possibly final -- season in Seattle, and though he’s sniffed October before, he’s never experienced it.

“I know me personally, I mean, good Lord, I'd like to make a run out of it,” Seager said.

On a broader level, this is territory that the Mariners haven’t found themselves in since 2018, when Seager and Seattle soared to first place in the AL West through June 13, occupied the AL’s second Wild Card on Deadline Day then tumbled out of contention despite winning 89 games, due in part to a huge second-half run by these very A’s.

Can the Mariners give the A’s a taste of their own medicine and supplant them in 2021? They certainly have promising ingredients, but there are notable needs -- such as within the starting rotation and for an infield bat, preferably right-handed. MLB.com’s Mark Feinsand reported Sunday that the club has pursued Kansas City’s Whit Merrifield.

• Surging Mariners targeting Merrifield (source)

“I think you're going to see a lot of movement around the league, no question,” manager Scott Servais said. “The teams that feel like they have a chance to go after a division title or a Wild Card berth, there's going to be a lot of movement. I think it all comes down to the last 72 hours, and being a part of a lot of those discussions, in my past, I realize how that all works.”

Still, the “are they for real or not?” questions will persist. But within a fiery and loyal clubhouse full of youngsters determined to buck the odds, the Mariners feel that they’ve done their part to push management to add.

Beyond Oakland, the Yankees (two games back of the Mariners) and Blue Jays (2 1/2) appear to be the only other threats for the final AL Wild Card, with Cleveland tumbling out and possibly on the verge of selling, and the runner-up in the AL East between Boston and Tampa Bay all but assuredly claiming the other spot.

“It's easy to say, ‘Yeah, go get that player or go get this player,’” Servais said. “It's really hard to make trades. I don't think people look at that and understand what's all involved with it, whether it's contracts, whether it's service time, how long you control a player, all those other things play into that.”

Skeptics are quick to point out Seattle’s -52 run differential, and how no team since the 2007 D-backs has reached October while being in the red in that category. Yet since June 13, when many within the clubhouse believe they turned the tide after Logan Gilbert outdueled Shane Bieber in Cleveland, Seattle has a +10 mark and has gone 23-11, a .676 winning percentage that trails only the Astros in that stretch.

Over the past two months, since May 25, the Mariners’ 32 wins are tied for fourth-most in MLB with the Dodgers and Red Sox, behind only the Astros (35), Brewers (34) and Giants (34). Each of the clubs on this list is expected to play into October.

The Mariners’ growing number of one-run games isn't exactly a red flag, but perhaps a yellow one. Constantly playing in close contests suggests that luck could be in play, but their success in those contests has hinged on a lights-out bullpen, which once again shut the door Sunday, with just one hit allowed -- a solo homer served up by Casey Sadler -- over 3 1/3 innings.

But a huge in-game turnaround by Marco Gonzales was the most notable performance on the mound. The veteran threw 49 pitches through the first two innings and had Servais “thinking we were in a really bad spot.”

Yet a mid-inning adjustment to focus more exclusively on his offspeed pitches -- no easy task mentally, especially against a disciplined lineup -- helped Gonzales push through and finish one out shy of six innings in what was his 100th big league start.

Their three-time Opening Day starter returning to form could be a huge internal boost over these final 10 weeks. But there is a lot of room to add externally, too -- and just a few days left to do so.