For the A’s, nothing really matters until the Wild Card Series begins on Tuesday. But with one game left in the regular season, they appear to be slumping entering the postseason.

Save for a two-homer performance by Robbie Grossman, the A’s offense continued to scuffle against the Mariners in a 12-3 loss in the second game of Saturday’s seven-inning doubleheader at the Coliseum. Swept in the twin bill, Oakland dropped to the No. 3 seed in the American League standings.

• Box score

The A’s were in trouble early on in the second game with an 8-1 deficit after three innings. Making his 2020 debut, Paul Blackburn lasted just 2 1/3 innings and was tagged for seven runs

“It’s not a great feeling,” A’s manager Bob Melvin said. “The first game was tough. We felt like we had a pretty good chance to win that game. Second game, we knew our pitching was going to be a little limited with guys we didn’t want to use. It ended up getting out of hand.

• Minor flashes impressive postseason value

“You just have to put the day away and come tomorrow knowing it’s the last day of the regular season and then the postseason starts.”

After clinching the AL West on Tuesday, the A’s stressed the importance of entering the playoffs with some positive momentum. On offense, that momentum is not great, as Oakland has been limited to three runs or less in six of its past seven games, and two runs or less in four of those seven after plating just four runs in 15 innings during the doubleheader.

Hitting with runners in scoring position has been an issue -- the A’s combined to hit 2-for-16 in such situations over the two losses. But not all hope is lost. A few key offensive contributors who were in slumps entering this series are showing signs of a turnaround, including Grossman, whose two-homer effort was the first of his career and part of a season-high three hits in the second game.

“He’s a key guy for us,” Melvin said of Grossman. “He’s a guy that gets on base and this year, for a period of time, was the guy that drove the ball and drove in some runs. We want everybody to feel good going into the postseason. He’s one of the guys, especially after today, that should feel very good.”

Others swinging the bat well are Matt Olson, who went 3-for-6 in the doubleheader, and Mark Canha, who is 4-for-7 with two doubles and a walk-off home run through the first three games of this series.

“Early in the first game, I was encouraged with our at-bats,” Melvin said. “Our situational at-bats weren’t very good, but I think guys are swinging the bats better across the board than what we saw four or five days ago.”

Could it be as easy as flipping a switch for the A’s come Tuesday? Maybe not. But regardless of what the numbers might be entering the postseason, Oakland’s hitters say they are confident.

“I have no doubt in this team. We won the division and we’re the best team in the division. I’ll take us over anyone,” Grossman said. “This last month has been a grind. We’ve played a lot of games. Three games in 24 hours, that rarely happens in a regular season. It’s been a grind. But everyone is looking forward to the playoffs.”