The Reds signed Chapman to a 6-year, $30.25MM deal in January 2010. They envisioned him as a starter, hoping his 103 mph fastball could dominate the major leagues. It hasn't worked that way so far. Chapman has started 16 games in the minors, but none in the majors. He has 69 appearances as a reliever. The Reds hoped to finally use Chapman as a reliever in 2012 and he did well as a starter this spring, striking out 18 and walking only 2 in 17 innings pitched. But the Reds' bullpen has thinned considerably this spring due to injury.
The Reds signed Ryan Madson to be their closer, but soon after he had to have Tommy John surgery, taking him out for the year. In addition, last year's set-up man Nick Masset will start the season on the 15-day DL and lefty Bill Bray missed most of spring training with a strained groin. With Sean Marshall moving into the closer's role, the Reds obviously didn't trust Bray to be the only lefty in the bullpen. It's unclear whether Chapman will move to the rotation when the team has more faith in Bray.