DENVER — This isn’t out of left field — the Los Angeles Dodgers are struggling against southpaws this season.

Latest to stymie them: Tyler Anderson.

The Dodgers had little success against the Colorado Rockies left-hander in a 7-0 loss during the opener of a doubleheader Wednesday.

Not all that surprising, considering Los Angeles is hitting under .220 when facing a lefty. The team squandered a solid outing from Ross Stripling (3-6), who surrendered three runs over six innings.

“Ross pitched well enough for us to win and you know left-handed pitching has been our Achilles heel,” said Dodgers manager Dave Roberts, whose team was held to six hits and went 0-for-7 with runners in scoring position.

“Teams going forward are going to run left-handers against us. So we’ve got to find a way to get guys on base and get them in.”

Anderson (5-5) allowed six hits in 6 1/3 innings against the NL West leaders. He also helped his own cause with an RBI single in the second in the team’s first shutout at Coors Field this season.

“It was nice,” Anderson said. “Tiring, but it was good.”

The doubleheader was necessitated by a rainout Tuesday. Anderson actually tossed a few warmup pitches before the first inning and then a relentless downpour blanketed the area, leading to a postponement after a delay of 2 hours, 32 minutes.

Colorado has taken the first two games in the series from the Dodgers. This is the fifth series the Rockies have captured from a first-place team in August. They’re the only team in the majors with a positive run differential (plus-26) and a losing mark (64-68).

Pinch-hitter Stephen Cardullo hit his first career homer in the seventh — on his birthday, no less. The 29-year-old Cardullo spent the last few seasons playing for an independent team in New York before signing a minor league contract with Colorado in January. He joined the Rockies last week after hitting .308 with 17 homers for Triple-A Albuquerque.

Anderson’s quirky delivery gave the Dodgers fits all afternoon. He briefly pauses before throwing to the plate.

The 2011 first-round pick wiggled his way out of a sticky situation in the sixth when the lefty had runners on first and third and one out. He struck out Adrian Gonzalez — the top daytime hitter in the majors this season — and then fanned Rob Segedin with a changeup.

Anderson trotted back out for the seventh, and left to an ovation with one out and two on. Chris Rusin bailed him out by striking out pinch hitter Yasmani Grandal and Howie Kendrick.

“We are going out of the strike zone and there are some counts where guys are swinging at a ball out of the zone,” Roberts said. “That changes the sequence in the at-bat.”

TRAINER’S ROOM

Dodgers: LHP Clayton Kershaw (mild disk irritation) had a successful outing in a simulated game Tuesday and now is in a momentary holding pattern. “We haven’t made the decision as far as what his next progression will be,” Roberts said. … LHP Scott Kazmir (neck stiffness) will be slotted into the rotation when he’s eligible to come off the DL on Sept. 7.

EXPANDED ROSTERS

Roberts gave an early glimpse of his plans for September call-ups. The Dodgers will add catcher Austin Barnes, righty Louis Coleman, lefty Luis Avilan — who will serve as the 26th man Wednesday for the second game — and righty Josh Ravin. Missing from that list is outfielder Yasiel Puig, who was demoted to the minors in early August.

“With Yasiel, that’s still a possibility, but we’re trying to figure out what’s best for him and what’s best for us,” Roberts said.

UP NEXT

The Dodgers scratched lefty Rich Hill (10-3) from the start in Game 2, going with righty Bud Norris instead. The team was concerned about a blister on his left middle finger. Colorado went with righty Jeff Hoffman (0-2).