Things fell apart for him and the Astros from there, as the D-Backs scored nine runs in the fourth en route to a 14-7 win.
McCullers made his feelings clear on the situation after the game.
"Opening the roof in the fourth is ass," McCullers said, according to Matt Young of the Houston Chronicle. "It's not an excuse. It just is what it is. Balls were being hit that were routine pop-ups and they were landing off walls. It was kind of just an unfortunate inning."
Astros manager Dusty Baker said the Diamondbacks told his team that the roof would be opened at some point.
''When they open the roof, this place plays like Colorado,'' Baker said. ''I knew before the game, this place, you never really feel safe here because of big gaps and the ball jumps and they start hitting the ball out of the ballpark. It seemed like when they opened the roof, the ball started carrying even better. They jumped us pretty good.''
Chase Field has a reputation for being a hitter's park. With the roof open, balls tend to fly even further. Six of the seven home runs hit by both teams during Wednesday's game came with the roof open.
"There was some routine balls that kind of carried up there and got deep," McCullers said, according to MLB.com's Brian McTaggart. "It got very dry. I was trying to lick my fingers. I was warned I couldn't do that. Obviously, COVID. … But like I said, the stuff was there. I felt really good. So, I'll just keep moving forward."