BALTIMORE -- The Reds activated lefty reliever Aroldis Chapman from the 15-day disabled list and optioned lefty reliever Jeremy Horst to Triple-A Louisville on Friday.Chapman had been on the DL since May 16 with left shoulder inflammation, but has been physically healthy for some time. Since Chapman has been out, Bill Bray has been very successful in Chapman's old role as the primary lefty setup man. Reds manager Dusty Baker plans to ease the 23-year-old Chapman back into the mix. "Hopefully we can get him in there in a lower-pressurized situation to see how he's doing," Baker said. "And then we can use him toward the end of the game, hopefully. We'll see the changes that he's made and hopefully he's back to where he was before." This season for the Reds, Chapman has 20 walks and 15 strikeouts in 13 innings and a 6.92 ERA over 16 games. Although Chapman's shoulder improved rather quickly with the rest, he was given a lengthy rehab assignment -- the maximum 30 days -- to get his mind right and his pitches under control. At one point, he spent nearly 10 days not pitching and working with pitching coach Bryan Price to straighten out his command Chapman had nine appearances for Louisville and Double-A Carolina, and his 30-day rehab assignment expired on Tuesday. He had an 11.12 ERA in four games for Louisville and a 6.14 ERA in five games with Carolina. His final two outings were solid -- each was a perfect inning. Even though Chapman does not speak English publicly, a translator wasn't needed to see his mood about the extended break from the Major Leagues. Speaking through trainer Tomas Vera, Chapman was curt, giving abbreviated answers. "Yeah, it was a little longer than I thought," Chapman said when asked about his time away. Was the extended time in the Minors longer because the club wanted to get his mechanics right, because of the injury itself or to get him set mentally? "I don't know. It was nothing about my mechanics," Chapman said. When asked about his final two outings, Chapman offered little insight. "Yeah, I feel good," he said.