MIAMI — Manager Don Mattingly says the Miami Marlins will find out a lot about their team down the stretch by being in a playoff race for the first time in more than a decade.

What they’re learning lately has been discouraging. Sputtering Miami hit into a team-record six double plays Sunday to cap a rough week with a 3-1 loss to the San Diego Padres.

The Marlins lost two of three to woeful San Diego and went 2-4 on their homestand while scoring only 13 runs, including just one run in the final two games.

“A couple of duds. It’s tough,” Mattingly said. “Two in a row like this, you feel horrible.”

Seeking their first playoff berth since 2003, the Marlins begin a seven-game trip Monday at the Mets. Their first-year manager was so wound up by the latest defeat he launched into a five-minute monologue with reporters.

“As bad as it looks right now in this storm we’re in, it’s still doable,” Mattingly said. “We’ve got to grow up, have an approach and be ready to play Monday. We can’t go into New York dragging our heads. We have to continue to play. These are things we’re going to learn about this club. If we’re going to move forward as an organization, these are the things we have to do.”

Rookie Luis Perdomo took advantage of the double plays to pitch his first career complete game, and the first this year for the Padres. Perdomo needed only 99 pitches to throw a six-hitter.

The most novel DP came in the seventh inning, when Perdomo gave up a one-out single before Ichiro Suzuki lined out to the pitcher, who trotted to first base to double off the runner.

“A little bit of luck in there,” Mattingly said. “There were some balls that were hit firm.”

Five Marlins hit into double plays, and they went 6-4-3, 4-6-3, 6-4-3, 6-3, 1, and 5-4-3. The six DPs were a nine-inning team record for the Padres defensively, and a Marlins batting record.

Perdomo lowered his ERA from 6.24 to 5.84 and beat Miami for the second time this year.

“He commanded his sinker well and got us to ground out,” said the Marlins’ Dee Gordon, who was erased twice on the bases by double plays and hit into a DP. “Hats off to him. He pitched a great game and kept us off balance.”

Justin Nicolino (2-6), making his first start since July 6, gave up three runs in six innings. That included a pair of two-out RBI hits.

“Two-out pitches you’d like to have back,” Nicolino said. “Those two runs cost us.”

Nicolino was called up from Triple-A to replace Andrew Cashner, who was scratched because of a finger blister.

Doubles by J.T. Realmuto and Xavier Scruggs in the second scored the Marlins’ run.

UP NEXT

Marlins: RHP Jose Fernandez (13-7, 2.91) is scheduled to start Monday at the Mets against RHP Rafael Montero (0-0, 11.57) to begin a four-game series. Fernandez is 3-5 with a 4.42 ERA on the road this year, but he’s 3-0 with a 1.54 ERA in seven career starts against the Mets.