Max Scherzer entered Sunday’s game two days off his normal schedule because of a comebacker that hit his right ankle area in New York the previous weekend and pushed his start back two days. (Tommy Gilligan/USA Today Sports)

If Wander Suero was going to throw a curveball, the Washington Nationals wanted him to bury it.

Manager Dave Martinez had summoned the reliever in the ninth inning Sunday against the Pittsburgh Pirates and charged him with maintaining a tie because closer Sean Doolittle had pitched two days in a row. Suero’s second high-leverage appearance in as many days seemed like an audition for the setup role the Nationals have struggled to nail down. Martinez trusted the right-hander against four consecutive left-handed hitters because to them, Suero’s best pitch — his cutter — runs inside.

Suero had a runner at second base with two outs, and he needed to escape. He threw his cutter three straight times to the Pirates’ Jason Martin. Then, ahead in the count 1-2, he tried a curveball.

“I thought he would throw him another cutter or a change-up,” Martinez said later. “His curveball is his fourth-best pitch, so . . .”

Suero left the pitch up and on the outer edge of the plate, and Martin smacked it to left-center. The ball dropped between center fielder Michael A. Taylor and left fielder Juan Soto, skipped into the bullpen for a ground-rule double and doomed Washington to a 4-3 defeat at Nationals Park.

“My catcher calls for the pitch after we had made a couple of pitches with the inside cutter, fastball,” Suero said in Spanish through a team interpreter. “I thought it was a good pitch to throw as well.”

Perhaps more frustrating for the Nationals than Suero turning to his curveball for such a pivotal pitch was the first at-bat of the inning. Suero jumped ahead 0-2 on the Pirates’ Josh Bell, who ravaged the Nationals’ pitching staff in this series and smacked two RBI doubles against ace Max Scherzer in the first three innings Sunday. In the ninth, Suero missed wide with cutters and change-ups and didn’t get one call that he thought he should have. Bell walked, advanced to second on a grounder and scored on Martin’s double.

In the bottom half, the Nationals loaded the bases and sent their two hottest hitters — second baseman Howie Kendrick and third baseman Anthony Rendon — to the plate with one out but couldn’t push a run across. Kendrick struck out looking, and Rendon flied out to end it.

The late-inning fold disappointed Scherzer, who overcame a rough start to pitch eight innings, allow three runs on seven hits and strike out seven.

“It’s frustrating,” Scherzer said. “The offense did a great job of battling. . . . We had opportunities to score and we just weren’t able to get it done.”

Scherzer was two days off his normal schedule after a comebacker hit his right leg in a game at the New York Mets the previous weekend. Before Sunday’s game, Martinez said Scherzer was “good to go,” but Scherzer didn’t look like himself early and later said his routine had been thrown off because he couldn’t run between starts.

In the first three innings, Scherzer allowed three runs on five hard-hit balls, including Bell’s doubles. And at the plate in the fourth, he tried to advance a runner from first base with a sacrifice, but the bunt stayed so close to the plate that Pirates catcher Francisco Cervelli threw to second to start an inning-ending double play.

The Nationals weathered the rough start mostly thanks to Kendrick. Early this season, the veteran slated to be Brian Dozier’s backup has excelled as a pinch hitter, forcing his way into the lineup. In his first start Saturday, the 35-year-old hit the eventual game-winning homer in the eighth to earn another start Sunday, when he raked again. He put the Nationals on the board with an RBI double in the first and scored in the third, keeping the score deadlocked at 3 and giving the Nationals wiggle room as Scherzer met with catcher Yan Gomes and pitching coach Derek Lilliquist in the dugout.

They formulated a plan to counter the Pirates’ aggressiveness: They decided Scherzer should throw more curveballs.

“It helped me to sequence a little bit better and steal some strikes,” Scherzer said. “Anytime you’re pounding the zone early with first-pitch strikes, it allows you to always beat counts and be driving pitches where you want them.”

Scherzer got locked in and retired 14 of the next 16 batters he faced. In the eighth, the Pirates’ Adam Frazier doubled and was still on second base when Starling Marte smashed a rocket just wide of third base. Rendon dived to his right and speared it. Frazier moved to third on the throw but never scored; Rendon had saved the Nationals a run.

One inning later, Rendon came to the plate with two down and the bases full against Pirates closer Felipe Vazquez, but he couldn’t contribute a run of his own, and Pittsburgh scored a series victory.