CHICAGO – White Sox closer Michael Kopech was not happy with Eddie Rosario's leadoff at-bat in the ninth inning of a 4-0 victory over the Nationals during Game 2 of a doubleheader Tuesday night.

And it showed.

Kopech struck out Rosario on the sixth pitch of the at-bat with a 99.7 mph four-seam fastball down the middle of the plate for the inning’s first out. Rosario wasn’t really there to see the pitch, as he seemed to walk out of the box as the pitch was thrown.

That maneuver led to Kopech saying something from the mound and waving his arm in disapproval, causing the Nationals to say something to him from their dugout. After reviewing the situation Wednesday morning, Kopech felt as if it was a bit of an overreaction on his part.

“I thought he was walking out of the box early on me, like remember David Ortiz doing that back in the day before the pitch even crossed the plate. I thought he was doing that, which I found disrespectful,” Kopech said. “I went back and looked and I think he saw it was a strike out of the hand and never had the intention to swing and was taking it back to the dugout.

“I probably didn’t react properly. I still would like for him to be in there for the full at-bat. I think that’s fair. But my reaction was a little bit much. And then their dugout was on me for it. It’s part of the game when reactions flare up like that. That’s all it was.”

Having not pitched since May 9 Kopech was understandably amped up on the mound. He had trouble locating his fastball, walking Joey Meneses and Luis García Jr. after the Rosario strikeout, before catcher Martín Maldonado moved Kopech to his cutter to get him back in the zone.

“My cutter, which typically starts and finishes below the zone, starts at the bottom of the zone and finishes below the zone, was kind of starting out off and coming almost right down the middle. But they weren’t seeing it well,” Kopech said. “They were just taking it.

“It was getting me back in the zone. I made some adjustments to find the zone again after that. I don’t think I threw too many fastballs, but once I did, I was able to get back down.”

Washington took the first 18 pitches Kopech threw in the ninth, with Nationals bench coach Miguel Cairo and assistant hitting coach Chris Johnson having some familiarity with his work as one-time White Sox coaches.

“They probably were telling them, ‘Look, if you don’t swing, then he’ll work a count on you,’” said Kopech, who came back Wednesday with two strikeouts and two walks to record his fifth save via a scoreless ninth during a 2-0 victory. “I think their gameplan was to kind of let me get myself in trouble and to their credit, I kind of did that. I don’t think they had the intention of going out aggressive.

“The last team I pitched against was Cleveland and that was the most aggressive swings I’ve seen in a while. So, it just depends on the approach, but there’s was to be patient and fortunately, it didn’t get out of control. It could have.”