SAN DIEGO -- When the San Francisco Giants arrive at Petco Park to open a four-game set on Thursday, the San Diego Padres figure to fling out a welcome mat after clubs' last meeting.

The Giants are still scratching their heads over getting swept by the visiting Padres from Sept. 12-14.

With a perfect opportunity to gain ground, or keep pace, with first-place Los Angeles Dodgers, San Francisco was blanked.

More from FoxSports

"We're at that time, you got to grind it out and find a way to get through this," Giants manager Bruce Bochy said after the Padres held his offense to five runs in three games. "We got to recover, this team has done a good job at that. They know what's at stake. It's a tough group. They've played under pressure like no other team."

The pressure is increased after the Giants dropped two of three to the Dodgers the past three days. Los Angeles (86-66) all but sealed the National League West title, grabbing a six-game lead with 10 to play.

San Francisco, meanwhile, slipped into a three-way tie for the NL's two wild-card spots. The Giants, St. Louis Cardinals and New York Mets are all 80-72.

The Padres (64-88) are concluding their sixth consecutive losing season, and they are tied with the Arizona Diamondbacks for last place in the NL West. San Diego took two of three games between the teams this week, though Arizona won the series finale 3-2 Wednesday.

Bochy and the Giants turns to right-hander Jeff Samardzija (11-10, 3.97 ERA) in the series opener against the Padres. San Diego will counter with southpaw Christian Friedrich (5-10, 4.78 ERA).

The Padres figure to field a new-look team after calling up four of their top position prospects on Wednesday: outfielders Manuel Margot and Hunter Renfroe, catcher Austin Hedges and infielder Carlos Asuaje.

"Everyone is going to play and everyone is going to get an opportunity," manager Andy Green said.

Asuaje, who led the Pacific Coast League with 172 hits, is ready.

"For all us to be called at the same time is great for me and for the organization as a whole," he said.

The quartet's call-up was delayed as they remain in the minors to win Pacific Coast League title with Triple-A El Paso.

"I think it adds so much value for us and gave us so much experience of building a winning culture here in San Diego, and that is what we want to do," Asuaje said.

Through a translator, Margot said he is thrilled to be a big-leaguer. He was a key piece in the November 2015 trade that sent closer Craig Kimbrel to the Boston Red Sox.

"We talked about getting here at the same time," he said of arriving with Asuaje, Renfroe and Hedges. "We are all very happy to be here."

Those four join two of their former El Paso teammates, infielder Ryan Schimpf and outfielder Alex Dickerson.

"I think we learned how to win together, and that was when Dickerson and Schimpf were there," Hedges said.

They will be here and there in the season's final weeks, sprinkled in various spots. Green said only first baseman Wil Myers will continue to play on a regular basis.