ATLANTA — Interim manager Don Mattingly wanted the Philadelphia Phillies’ best reliever on the mound as early as possible in a tight opening game of a best-of-three National League Wild Card Series against the Atlanta Braves.

Turning to All-Star closer Jhoan Duran in the seventh inning made it appear Mattingly was hoping his best reliever could cover the final three innings and protect a beleaguered bullpen.

After Duran gave up a three-run homer to Austin Riley in the eighth inning of the Phillies’ 5-3 loss to the Braves on Tuesday, Mattingly and Duran faced questions about why the manager turned to his closer so early in the game and whether he was asking too much from Duran.

“I threw the first inning and I go back to the dugout and they said be ready for another inning, and so I go back out there and try to do my work,” Duran told reporters.

Duran’s perfect seventh inning only emboldened Mattingly’s plan to stick with the closer in the eighth. Mattingly might have hoped the 28-year-old Duran could pitch three innings to protect a 3-2 lead, even though he made just one multi-inning appearance in the regular season.

“He made it look easy the first inning,” Mattingly said of Duran. “If the second one would have went really quick, I would have just checked with him. If not, we would have went to somebody else.”

Unfortunately for Duran and the Phillies, his second inning — the eighth — was not quick or successful. Duran gave up a two-out single to Michael Harris II before hitting Ozzie Albies with a pitch and allowing Riley’s shot that put Atlanta in the lead.

“Anytime you lose a game late, obviously it’s frustrating, but in our minds, we had our best guy out there,” Mattingly said of Duran. “You live with this one.”

When asked if he turned to Duran in the seventh because the Braves had the top of their lineup coming up, Mattingly said it wasn’t a matchup decision.

“Not with Jo,” Mattingly said. “We don’t really worry about the matchup. It was more the spot.”

Duran (0-1) allowed just two homers in 61 regular-season games. He was successful on 33 of his 35 save opportunities, but others in the Phillies’ bullpen did not enjoy the same success.

Philadelphia’s relievers had a 5.79 ERA in September, worst in the majors.

Mattingly was asked about his ninth-inning plan if Duran had protected the lead in the eighth.

“It depended where we landed,” Mattingly said. “We had [Jonathan] Bowlan. We had different guys; we’d probably combo the inning a little bit. If [Duran] gets a quick out, we’ll check with him and we see.”

Mattingly said Andrew Painter, a starter in 23 of his 25 games this season, could have been another ninth-inning option.

The Phillies now turn to left-hander Cristopher Sanchez to start Wednesday’s must-win second game of the series.

“It doesn’t matter if it’s Game 1 or 2, just keep focused on what we have to do and follow the game plan,” Sanchez said before Tuesday’s game. “It’s not that difficult at all. It’s just a matter of being able to wait it out.”

Mattingly acknowledged the Phillies face another must-win scenario after being stretched to the final game of the regular season to clinch a wild-card spot.

Mattingly said his players will “show up and play.”

“These guys have been here before, so that game the other day felt like a must-win,” Mattingly said.

“We’re back there tomorrow.”

Mattingly said he’s confident having Sanchez for Game 2.

“Always feel good with Cristopher out there,” Mattingly said. “The playoffs are momentum-based, it seems like, and really momentum starts with your starting pitcher. He goes out and gives you a good start to the game … it’s just a game at that point.”

Duran’s availability on Wednesday is uncertain after he threw 27 pitches while allowing three runs in two innings.

“We’ll check tomorrow, like we always do,” Mattingly said. “We let guys go throw, see how they are, and then we decide.”