Sunday, the inevitable occurred. Chapman's talent and the needs of the Cincinnati Reds intersected and the 24-year-old left-hander got the ball and the save opportunity in the ninth inning against the New York Yankees.
Four batters later, Chapman had the save. The Reds, meanwhile, had a 5-2 victory, and a series victory over the Yankees. Beating the Yankees in the Bronx is always a big deal, even moreso in this case, because the Yankees entered this season with baseball's best Interleague record over the 15 seasons of Interleague Play.
For Chapman, this game appeared to be nothing out of the ordinary. He was throwing fastballs 96-99 mph, a controllable velocity for a man who has thrown 105 mph. He got Nick Swisher on a foul pop, saw pinch-hitting Mark Teixeira reach on a throwing error from Wilson Valdez, then got Russell Martin, also pinch-hitting, on a fly to right. The Yankees, trying every right-handed bat they could find against Chapman, then pinch-hit Andruw Jones. Chapman struck out Jones on a 98-mph fastball to secure the victory.
The degree of difficulty is substantial pitching against the Yankees, especially in Yankee Stadium. Chapman did not appear to be troubled by any of these circumstances. He had graduated from pitching the eighth inning as a setup man to pitching the ninth as a closer, but he did not allow himself to feel additional pressure.
"To me, I feel the same, I feel normal, the way I've been doing it," Chapman said through an interpreter, Reds associate athletic trainer Tomas Vera. "Either inning for me is the same. All that was in my mind was just to throw that inning and get the outs.
"I never felt the extra pressure. Maybe one day things could get complicated and I could get some kind of pressure, but now, I never felt that."
The only problem Chapman encountered came in the form of two holes on the mound in what would have been the landing area of his delivery. He politely asked for the Yankee Stadium grounds crew to fix the holes, and the mound was repaired to his satisfaction.
"There were two holes there, and I asked please to cover them, because I pitch with the flat ground, I don't like to land in holes," Chapman said. "They fixed it really well."
There had been concern that Chapman might not be available on Sunday because he had pitched in three of the last four games. This wasn't a problem for him, either.
"I never felt bad; I felt great the whole time," Chapman said. "It never went through my mind, the fact that I was pitching the days before."
Before the game, Reds manager Dusty Baker had said: "Chapman is my No. 1 candidate [as closer]." But Baker had also said regarding Sunday's game: "I need to stay away from Chapman, he's [pitched] three out of four days."
After the game, Baker said that after making those comments, he checked with Chapman, who told him he was perfectly fine.
"We try to go on the honor program here," Baker said. "Let us know if you're not right, if you're tired or aching or whatever it is. This isn't hero time yet. August and September might be a little bit different, but right now we're trying to get these guys healthy and through the season."
Baker might not want to use Chapman for a fifth time in six days if a save situation arises against the Atlanta Braves on Monday night, though. There are other options, Baker noted. He could go back to Sean Marshall, if the opposition hitters are predominantly left-handed, or to Logan Ondrusek to get right-handed hitters out.
The Reds will obviously monitor Chapman's usage closely. But they don't need to worry about his lack of experience as a closer. His ability and his competitive nature should continue to work well for him in his new role.
"He didn't have the experience of being a setup man, either," Baker said. "We were graduating him to this point. Just don't thrust him in there. We talked to him and asked him if he was mentally ready in case this decision came down. He said he was, so we took him at his word."
In a closely related development, Marshall was moved back into his accustomed role as an eighth-inning setup man. Marshall came into a 3-2 game with one on and no outs in the eighth and did his job to the utmost, striking out Robinson Cano.
Marshall had considerable success in a setup role with the Cubs. He was thrust into the closer's role with Cincinnati only because Ryan Madson was lost to Tommy John surgery. Sunday's role was what the Reds intended for Marshall in the first place.
"That's the role that he's accustomed to doing," Baker said. "Everybody has a comfort level. He was in the closer's role because he was most qualified at that time."
Marshall took the change of assignment exactly as the Reds hoped. "I'm a do-what's-best-for-the-team kind of guy," Marshall said. "I know what I do best, and I don't plan on changing how I pitch in any different role. I'll keep doing that, whether it's as the closer, a setup guy or a one-out guy. Whatever it takes to win the game."
The Cincinnati Reds have, by the numbers, one of baseball's best bullpens. With the arrival of Aroldis Chapman as closer, this bullpen just became even better.
Mike Bauman is a national columnist for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.