Erick Fedde delivered the best start of his young career in a win over the Phillies on Tuesday. (Katherine Frey/The Washington Post)

PHILADELPHIA — Erick Fedde was not pleased when he saw Manager Dave Martinez emerge from the Washington Nationals‘ dugout and start toward the mound.

And why would he be?

Fedde is a budding major league starting pitcher, a noted competitor, conditioned to focus all his energy at the hitter standing 60 feet, 6 inches away. So there he was Tuesday evening, on the mound at Citizens Bank Park, watching Martinez get closer and hoping it did not mean he was out of the game. Fedde admitted later, with a laugh, that he was saying some “unhappy things.” But Martinez did not plan to hook Fedde, not right away, not before talking to the pitcher to see what he had left in the first game of Tuesday’s doubleheader.

I asked him, ‘What do you got?’ It’s time I treat you like a big boy,” Martinez said after the game. “He said, ‘I want to get him out. I said, ‘Well it’s your game, go on and get him out.’ ”

Instead, Fedde walked Rhys Hoskins and was taken out once ball four was thrown. But Martinez’s decision in that situation — with a runner already on, two outs in the sixth of a close game and one of the Phillies’ best hitters coming to the plate — hinted at the progress Fedde has made this month. Fedde, 25 years old, was the Nationals’ top pitching prospect coming into this season and then missed most of the summer with a shoulder injury. Tuesday’s start was his second since coming off the disabled list. It also turned out to be the best start of his young career, as he delivered 5 2/3 scoreless innings, just two hits and struck out a career-high nine hitters.

He had never finished a start with fewer than three runs on the scoreboard. He has also never received so much trust from his manager.

My fastball felt great today,” Fedde said. “I was able to command it on both sides of the plate and I really just think it just opened everything else up.”

In his first start back from the injury, on Sept. 4, Martinez thought Fedde went away from his fastball and was too reliant on his slider. Fedde threw three scoreless innings against the St. Louis Cardinals, facing 13 batters, allowing no hits and one walk. But he was burned by a shoddy fourth inning that ended with four earned runs on his line.

He agreed with Martinez’s assessment, saying his slider felt good but he should have thrown more fastballs. His chance to put that advice into practice was then twice delayed by rain, on Sunday and Monday, yet Fedde still jogged into the outfield both times to keep his arm loose. Since undergoing Tommy John surgery in 2014, Fedde feels his arm stiffen if he takes a day off from throwing. That worried Martinez these last few days, particularly when Fedde was throwing in shorts and a t-shirt in the rain, but Tuesday’s results justified the approach.

He was attacking the strike zone. he was really good,” Martinez said. “Kept the ball down, used all his pitches. He was good. I wanted to give him a chance to go out there and face Hoskins, he said he felt great and was throwing the ball well so he did really well.”

The helped the Nationals sweep their second doubleheader in four days and gave Fedde his second victory of the season. But it mattered much more when viewed through a wide lens. The Nationals are 73-72 with 16 games left to play. They are nearing mathematical elimination despite a four-game winning streak. The biggest takeaways from this September will be the ones for the future, like the standout play of 19-year-old left fielder Juan Soto, or the emergence of young arms in the bullpen, or Fedde showing that he could help round out next season’s starting rotation.

When the Nationals’ start constructing their staff of the future, there is Max Scherzer, Stephen Strasburg, Tanner Roark and two question marks in the back end. Those slots could be filled in free agency, or internally, or some combination of  both, and Fedde should have two more chances to state his case for one. On Tuesday, his evidence included a two-seam fastball that kissed the mid-90s and tailed at the end of its path. It included a reliable slider that wasn’t overworked. It included the confidence to face Hoskins, whatever the result, as his pitch count climbed to 100 pitches.

And, for at least one evening of this looking-glass September, it was all hard to ignore.

Read more on the Nationals: 

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The Nationals’ approach to all these rain delays? ‘Whatever will keep you sane’