LOS ANGELES -- It's all hands on deck for the San Diego pitching staff at Dodger Stadium this weekend.

As regular-season series go, the nature of the Padres' four-game set in Los Angeles is certainly unique. The All-Star break waits on the other side, offering four days of rest. Plus, San Diego currently has seven starting pitchers on the roster, with Dinelson Lamet's return from Tommy John surgery and Cal Quantrill's move back into the rotation.

It's also a critically important series that might define the Friars' first half. After a hot start, San Diego opened the series having dropped four straight and sitting two games below .500.

With a thin bullpen and an overcrowded rotation, the Padres decided they'd be best served to use a few starters in the bullpen. Lefty Logan Allen, who started Monday, was available for Thursday's series opener. Matt Strahm and Quantrill will join him in the 'pen later this weekend.

"This is a big series against the Dodgers," Strahm said. "Everyone's on deck, and I don't think that's just a pitching thing. It's a mentality for the whole team."

The Padres will almost certainly open the second half with a combination of Lamet, Joey Lucchesi and Eric Lauer against the Braves, before an off-day, giving all three of their starter/reliever hybrids plenty of extra rest.

In fact, the Padres will have some decisions to make on the rotation status of those three after the break, when they'll probably pare their group of seven starters down to five.

But don't expect those extra starters to head for Triple-A. It just so happens that the Padres could use some long-term bullpen help as well. Their 4.97 relief ERA is the second highest mark in franchise history, and it ranks 24th in the Majors this season.

That group would almost certainly benefit from the addition of, say, Strahm, who posted a 2.05 ERA in 41 relief appearances last season. Quantrill has already been a useful bullpen piece this season, and Allen could do the same.

"There will be a lot of information to glean from these four games," said Padres manager Andy Green. "It's a chance to see guys pitch in high-leverage situations out of the bullpen, some who have never done that before, some who haven't done it since last year, and to see what we get from them in those situations."

Allen, for instance, hasn't pitched as a true reliever in professional ball. He made six relief appearances in the Minors, but those were exclusively planned piggyback situations.

"I'll throw harder, let it eat a little bit more," Allen said. "And I'm able to throw the offspeed a little bit more. I don't have to worry about setting up hitters and going through the lineup a second time. ... I can attack hitters with all four of my pitches right away."

The extra relief help could prove hugely important this weekend. Kirby Yates has locked down the closer role, but the Padres have struggled getting the ball to him. They've been particularly shaky in the middle innings.

Now, in what's arguably their most important series of the season, they'll have a few extra weapons to help bridge the gap to Yates.

"We all know what the job is," Strahm said. "We know the break's coming, and these four games are important. These four games are what we've got to focus on. We'll worry about what's after the break after the break."

"It's time to start making a push," Allen said. "It starts now. We've got to take care of business this weekend and go from there."

Noteworthy

• Franchy Cordero's extended absence could linger into September, Green said Thursday, a blow to the Padres' bench, even though their outfield is already deep. Cordero played nine games this season before missing two months with a right elbow sprain. As he approached his return, Cordero sustained a quad injury during a rehab game in mid-June.

"It was a serious enough injury that there were some tendon issues along with it," Green said. "That's not a quick healer. ... He's out for a while."

Cordero's speed, defense and left-handed power would play nicely in the Padres' righty-heavy outfield mix. But he's spent most of the past two seasons sidelined with various injuries.

• Lefty reliever Jose Castillo threw a bullpen session on Thursday, as he works his way back from a flexor strain in his left forearm. Castillo was pitching in what would have been his final rehab appearance on June 10 when he exited after 10 pitches with tightness. The Padres shut him down temporarily, but Castillo could be in line to resume his rehab stint after one more 'pen session, Green said.

Castillo hasn't pitched since Spring Training, and his absence has hit the bullpen hard. He posted a 3.29 ERA with 52 strikeouts in 38 1/3 innings last season.

• The Padres designated right-hander Matt Wisler for assignment last week. On Thursday, they dealt him to Seattle for cash considerations. In 21 appearances for the Padres, Wisler posted a 5.28 ERA.

• Robert Stock was placed on the 10-day injured list with a right biceps strain. Fellow righty reliever Gerardo Reyes was recalled in his place. Meanwhile, lefty Brad Wieck was optioned to Triple-A El Paso to clear room for Lamet's return.