"He's been told you don't have to throw 100 mph to be successful," Reds general manager Walt Jocketty said.
The early results have indicated exactly that. Through nine appearances, totaling 12 1/3 innings, Chapman hasn't allowed an earned run. It's the best scoreless mark of any reliever, just ahead of Tigers reliever Duane Below's 12 scoreless frames.
Chapman, 24, is second on the Reds with 21 strikeouts, compared to only four walks and five hits. He had 18 strikeouts over 10 innings before issuing his first walk on April 22 in Chicago.
"What has made me happy so far is my command and the small amount of walks I have so far," Chapman said through an interpreter. "I worked a lot during the offseason and a lot during Spring Training. It helped me have the command I have now."
Chapman has evolved into a pitcher instead of a powerful novelty. No longer relying so heavily on his fastball, he's integrated other pitches into his bag of tools -- including a slider and a two-seam fastball.
"So we have a heater that can come under the hands -- and if you see guys really turning to try and get the head out, you give them the two-seamer," Reds catcher Ryan Hanigan said.
Last season, the Reds saw how bad things could get when Chapman was out of whack. In one four-appearance streak, totaling only 1 1/3 innings, he gave up 10 runs and 12 walks. Chapman was placed on the disabled list with left shoulder inflammation. Upon recovering, he was given the full 30 days of a rehab assignment in the Minors to straighten out mentally and improve his mechanics.
Chapman's mechanics this year, under the watchful eye of pitching coach Bryan Price, have become more repeatable. And he is working faster on the hill.
"The biggest difference is his tempo," Hanigan said. "He gets the ball, gets right on the mound and he doesn't dwell on throwing a ball or walking a guy. He gets right back in and it looks to me that all that's going through his head is making the adjustment to get his mechanics working like they should, if they're not. And if they are, he just goes right at you and keeps coming."
With the physical improvements has come one big mental one: Chapman is pitching smarter.
"The main thing is he seems to have better focus," Jocketty said. "He seems very confident with what he's doing, which is important."
Chapman had his biggest challenge of the season in his most recent appearance, on Saturday vs. the Astros. Called from the bullpen to finish a 6-0 Reds shutout in the top of the ninth, he walked the leadoff batter, gave up a one-out single and issued a two-out walk.
Chapman, however, proved unflappable.
Against Chris Snyder, he escaped with a 96-mph fastball with movement that drew a swing and a miss for strike three. Chapman walked off the mound with a smile on his face and shook hands with Hanigan.
"Honestly, everybody was excited about that velocity," Hanigan said. "It's hard for a guy to pitch like that. I don't care who you are. He's shown the arm strength but also shown the maturity. He'll throw 97 for a ball, 95 ball and 93 strike, 95 strike and 97 back up. He doesn't try to blow it out when he doesn't need to. That's pitching. That's growing up. It's great."
In January 2010, after his defection from Cuba, Chapman was signed by the Reds to a six-year, $30.25 million contract with the expectation that he would be a starter. But through 78 big league games, he still has zero starts.
In some circles, there have been some howls that the Reds are blowing a lot of money for a setup man. In late 2010 and last season, Chapman was used out of the bullpen to keep his innings down. This season, while the club acknowledges that Chapman's long-term future is as a starter, using him as a reliever in the short term is a necessity.
Chapman was the best starting pitcher in Spring Training, but a season-ending elbow injury to closer Ryan Madson, plus injuries to setup men Nick Masset and Bill Bray, forced the Reds to keep him as a late-inning reliever. Moving Chapman to the rotation at some point this season remains on the table, according to Jocketty.
"It's not on the front burner," Jocketty added. "Right now, he's serving an important role in the bullpen. Until we get healthy there, it'd be hard to take him out of that role."
Working as a starter in camp has Chapman stretched out enough that he has often worked two innings in his outings -- twice earning victories. It's also kept Price and manager Dusty Baker cautious. Giving Chapman two innings and around 35 pitches means he'll be unavailable for a couple of days.
It's not always easy to avoid using Chapman, but the Reds' bullpen has filled in nicely around him, posting a 2.82 ERA as Logan Ondrusek and Jose Arredondo have stepped up to complement Chapman and new closer Sean Marshall.
"In the bullpen, you can pitch every day, but the coaching staff and manager have been carefully using me in a way that my body recuperates," Chapman said. "That's the key. I don't have any problem with that. I feel good and comfortable with the way I've been used."