"I'm proud of the kid," manager Andy Green said of the 23-year-old Perdomo. "You see him continue to develop. That's a tough offense that he just navigated. You can tell by the swings they take that it's an uncomfortable at-bat. It's not something guys want to face."
Perdomo's development this season has been stark. On Opening Day, he allowed six runs in one inning out of the bullpen and, according to Green, looked "shell-shocked on the mound." Since then, he has improved gradually, and in the four starts leading up to Friday, he had a respectable 3.97 ERA.
Then came Friday's career night. Not only had Perdomo never completed seven innings in a start before facing the Nationals, he had never allowed as few as four hits in any outing lasting longer than three innings. But on Friday, he made only one mistake, a sinker Jayson Werth hit out of the park in the first inning, and faced only one jam, a two-on, one-out situation in the fourth he promptly pitched out of by striking out Trea Turner and getting Danny Espinosa to fly out to center.
As usual, the righty pitched to contact, keeping his sinker low in the zone and inducing 13 ground-ball outs.
"I was able to stay aggressive, stay ahead of guys, keep the ball down and just be aggressive with my sinker, and it got ground balls," Perdomo said.
Perdomo also found success with a changeup he said he worked hard on this past week. To Green, the way the rookie used that pitch was emblematic of his "exponential" growth as a pitcher.
"All of a sudden he's got a changeup. Like where'd that come from?" Green said. "Every single time out he's featuring not necessarily a new pitch that he didn't have before, but a more effective version of that pitch from the work he does in between."
Alex Putterman is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.