WASHINGTON -- Christian Scott knew it immediately.

For much of his return to the big leagues on Wednesday, Scott, the Mets’ second-ranked prospect, had the Nationals off-balance. His first time through their batting order, Scott didn’t allow a hit. But after limiting damage in the fifth, having allowed the first three batters to reach, Scott was faced with a two-on, two-out jam with a four-run lead in the following frame.

On a 1-0 pitch to Luis García Jr., Scott snapped off a sweeper that initially seemed destined to meander out of the zone. The sweeper didn’t sweep, however, hanging instead over the middle of the plate. When García swung at it, Scott took a quick glance up but didn’t bother to watch the ball’s flight, as it landed in the second deck in right for a three-run homer.

New York’s shorthanded bullpen quickly gave away the rest of the lead in a 7-5 loss at Nationals Park.

“I was trying to squeeze one more hitter [out of him],” Mets manager Carlos Mendoza said. “That didn’t work.”

That it didn’t work was simply a matter of execution; Scott was trying to bury the sweeper inside, but it hung over the plate where García could launch it for one of his two homers. Even then, the Mets retained the lead … but one-run leads hit differently these days given the state of their bullpen.

With Edwin Díaz suspended until Friday and several other relievers injured, the Mets have struggled to find a reliable bullpen mix. Wednesday, Mendoza turned in the seventh inning to Jake Diekman, who allowed three consecutive baserunners -- plus the tying and go-ahead runs -- before recording an out.

“It’s kind of like a revolving door,” Diekman said of the current state of the relief corps.

While that unit waits for potential reinforcements on the trade market, one thing the Mets can do to support it is have their starting pitchers last deeper into games. Tylor Megill wasn’t doing that, which is part of the reason why the Mets recalled Scott on Wednesday to replace him following a monthlong sojourn to the Minors.

Scott’s stay at Triple-A was always meant to be temporary -- the product of a schedule that afforded the Mets six off-days over a 22-day stretch in June. All that downtime made a six-man rotation untenable, so the Mets sent Scott to the Minors. Their hope was that the 25-year-old could continue to refine his game there while also keeping his workload low. Over four starts at Triple-A Syracuse, Scott averaged 68 pitches per outing.

Whether that resulted in a tired arm as Scott pitched into the sixth inning of a game for the first time in six weeks isn’t clear; the rookie danced around a question regarding his fatigue level later in the game. Mostly, he bemoaned his execution throughout the night, which saw him generate just six swings and misses on 99 total pitches. Scott’s whiff rate of 12 percent was his lowest in any of his six big league starts to date.

Overall, the right-hander allowed four runs in 5 2/3 innings, with two strikeouts and two walks.

“This one’s on me tonight, for sure,” Scott said. “But at the same time, you’ve got to take the positives and learn from the negatives.”

Given the early success that Scott had in the Majors, it can be easy to forget how young and inexperienced he remains. He has thrown just 219 2/3 innings in his professional career after spending almost the entirety of his college experience in the bullpen. The Mets still have high hopes for Scott, who went from being unranked on MLB Pipeline’s Top 100 prospects list at the start of Spring Training to his current perch at No. 38 -- the ninth-ranked pitching prospect in baseball.

One lackluster start -- make that one lackluster pitch, actually -- won’t do much to alter Scott’s trajectory as one of the game’s rising pitching stars. It was simply a reminder that his development is not yet complete.

“He was really good again,” Mendoza said. “He was on the attack. The fastball was playing. This is an aggressive team, and he didn’t back down. He was on the attack. He got quick outs when needed. So yeah, I thought he was really good -- other than that pitch.”