SAN DIEGO -- It was a four-game series against the D-backs that the Padres welcomed. A chance to make up ground in the NL Wild Card race and put their late-season push for a playoff spot into overdrive.

Instead, San Diego wobbled and stumbled like an old jalopy and that was never more evident than Saturday, when the Padres were swept aside in a doubleheader.

The Padres fell in the night portion of the twin bill, 8-1. That came on the heels of a first-game hiccup that resulted in a 6-4 loss.

Two more losses, and just as importantly, two fewer chances to make hay against one of the half-dozen teams ahead of them in the Wild Card standings. The sweep left the Padres 5 1/2 games back of the final NL Wild Card spot.

“It was a long, miserable day,’’ Padres manager Bob Melvin said after losing three of four to Arizona. “It certainly was not what we expected, what we wanted.’’

The star-studded Padres constantly talk about how they can turn it around. That’s great, but the switch needs to be flipped pronto.

Yu Darvish struggled early, which accelerated his pitch count. He hit the first batter he faced, and in the second inning, Arizona poked him for two runs.

Christian Walker opened with a single and scored on Alek Thomas’ double. After Gabriel Moreno grounded out, Jake Cronenworth tried to catch Thomas advancing to third, but Manny Machado was handcuffed by Cronenworth’s short-hop throw, the ball got away and Thomas scored.

That 2-0 edge grew to 3-0 in the fifth when Walker’s flare to right pushed across Corbin Carroll. Darvish, who has one win since July 20, wasn’t around much longer. He exited in the sixth without recording an out after 104 pitches. He allowed four runs on nine hits and one walk, with seven strikeouts.

“Obviously, it was a long day for us,’’ Darvish said through an interpreter. “You really don’t want to drop two games here, but that’s what happened.

“My control wasn’t at its best and I think they were getting the bat to the ball. You have to tip your hat.’’

The Padres pulled to within 3-1 when Xander Bogaerts homered in the fifth, a Statcast-projected 409-foot shot that came off the bat at 106 mph and it rattled the Western Metal Supply building in left field.

But the Padres would get no closer.

Arizona added a run in the sixth, then Moreno’s grand slam in the seventh removed any doubt.

“They completely outplayed us,’’ Melvin said.

So what’s the mindset inside the clubhouse of MLB’s third-highest paid team that is seven games under .500 (just one off their season high) at 59-66 and 5 1/2 games back in the Wild Card standings?

“We need to do the things we are doing -- we are hitting balls right at people,’’ Juan Soto said. “We are crushing balls and they are going to land someday.’’

San Diego’s Game 1 loss came with a gut punch.

The Padres rallied to tie the game twice, but they were faced with erasing a three-run deficit before recording their final nine outs.

After pulling to within 6-4 in the eighth, San Diego loaded the bases with two outs in the ninth and Soto at the plate.

When Soto sent a deep drive to left field, the home dugout erupted with players anticipating a walk-off grand slam. It would have not only delivered a win, but an infusion of confidence to a squad that has had the swagger, but not the results.

“It was a tough loss,’’ Machado said. “We battled back and came up short.’’

When Soto’s effort died on the warning track, some life was sucked out of the Padres, too.

“We’ve been hitting the ball hard, but just right at people,’’ Soto said. “It’s just baseball. We have been grinding all the way, but things just aren’t going our way.’

Melvin agreed.

“This has not been the easiest season in the world,’’ he said between games. “And it seems like everything that can go wrong, does.’’

The Padres, of course, weren’t eliminated and no one was administering their last rites. But with only 37 games remaining, the fading club needs to pull a rabbit from its cap.

“We have the ability to do it and everybody knows that,’’ Melvin said. “We have to actually do it. We have to play better baseball consistently, and it hasn’t happened all year to this point.’’