This was anything but an exhibition for Astros right-hander Lance McCullers Jr. The chance to pitch in a game in a big league stadium and take the ball Monday night against the Royals represented a significant step forward in his recovery from the Tommy John surgery that cost him the entire 2019 season.

McCullers’ return to the mound was delayed because of the coronavirus pandemic, and he admitted he quit counting the days back to his surgery months ago. The biggest benchmark of his recovery will happen when he makes his first regular-season start in nearly two years Saturday against Seattle in Houston.

• Box score

But if Monday was any indication, McCullers is back.

McCullers turned in a strong performance in his final tuneup before the start of the regular season by holding the Royals to one run and four hits in five innings during a 6-3 exhibition win at Kauffman Stadium in Kansas City.

“The word of the day for me was ‘grateful,’” McCullers said. “I was grateful for the ability for the stars to align for us to play tonight with the weather that was possible. Grateful for my teammates and the opportunity to pitch on a big league mound. It was a good day.

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McCullers struck out six and didn’t allow a walk while throwing 75 pitches, the target pitch count manager Dusty Baker laid out before the game. That should put McCullers in line to potentially throw 90 or so when he faces the Mariners on Saturday.

“He was really good,” Baker said. “He had real good command of his fastball, had good velocity and his breaking ball was sharper and in the zone more than it had been. We wanted to get to 75 pitches, and he went right on the nose.”

The Astros flew to Kansas City midday Monday and went straight from the airport to the stadium. Teams typically fly in the day before, and starting pitchers often fly ahead if the team is planning an early-morning arrival. The Astros debated whether they would travel Monday morning because there was an 80-percent chance of rain in Kansas City.

“I was really happy to be able to come here today,” McCullers said. “We took a little bit of a gamble knowing it may rain, but it was one we felt was worth taking because I wanted to get some game action in, some real game action. For me, I’m very grateful to get to this point. A lot of hard work has gone into getting here with the medical staff and the trainers and my teammates pushing me. Tonight was more an exhibition game for me.”

The Astros broke the game open in the fourth inning against Royals starter Mike Montgomery, thanks in part to a two-out fielding error by Maikel Franco. Outfielder Josh Reddick bopped a two-out, two-run homer and two batters later, catcher Martín Maldonado hit a two-run homer off Montgomery to give the Astros a 5-0 lead.

The only run McCullers allowed came on a two-out solo homer by Royals catcher Salvador Perez in the bottom of the fourth off a changeup McCullers tried to sneak past him. Despite being well-known for his elite fastball and curveball, by throwing 18 changeups Monday, McCullers is clearly growing more confident in his third pitch.

“I was happy with the ability to throw it for strikes, expand the strike zone with it. It’s been good for me the whole camp and it was good for me today,” he said.