CINCINNATI — Left-hander Aroldis Chapman had an MRI exam on Monday that found inflammation in his pitching shoulder, sending the Reds reliever to the 15-day disabled list.
The Reds said the problem contributed to his wildness in his last few appearances. Chapman walked 12 batters and retired only four in his last four outings. Twice, he left the game without getting anyone out.
The worst appearance yet was Sunday, when Manager Dusty Baker brought him in to pitch the ninth inning with a 9-2 lead against St. Louis. Chapman walked four of the five batters he faced, throwing 18 balls in 23 pitches. The Reds held on for a 9-7 win that kept them in first place in the NL Central.
Right-handed reliever Jordan Smith was recalled from Triple-A Louisville to take Chapman's spot before the opener of a two-game series against the Chicago Cubs.
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"It was affecting his mechanics," Baker said. "You can see the last few outings, he hasn't been the same. He really hasn't complained, either."
The 23-year-old Cuban defector has struggled with his role in the bullpen this season. The Reds signed him to a six-year, $30.25 million contract last year, expecting him to be a starter. With the rotation full, they moved him into relief in the second half of the season, when he was pitching in the minors.
He was called up for the stretch drive and hit 105 mph on radar guns, helping the Reds win the NL Central. They decided to keep him in the bullpen for one more year and had him there from opening day. He developed tenderness in his elbow last month, forcing him to rest for a few days.