In the wake of Manny Corpas' trip to the DL, the Rockies found their relief staff of RHP named "Manny" severely depleted, and dipped into the wealth of minor-league pitching prospects to patch the wound via trade.
Manny Delcarmen, in 44 innings stretched over 48 games, has posted a 4.70 ERA, a 3-2 record with no saves, a 5.69 FIP and 5.18 xFIP, and a strikeout-to-walk ratio of 1.14.
Balcolm-Miller, in High-A Asheville, has posted a 3.31 ERA in 19 starts, going 6-7 over 108.2 innings, striking out 117 and walking 19.
Over the past 2 seasons, Delcarmen has seen his role as setup-bridge to Jonathan Papelbon dimish as his control began to fall apart (5.73 BB9 in 2010) and ability to get batters out on strikes also declined (6.55 K9). While still a serviceable reliever, Delcarmen has showed a decreasing ability to handle high-leverage situations, as evidenced by his -.31 WPA in 2010.
Along with his excellent K/BB ratio in Asheville, Balcolm-Miller has also shown a great tendency to keep the ball on the ground, posting a 2.13 GO/AO this season.
I personally feel we overpaid for a struggling, declining reliever who we've wanted for years, in hopes of shoring up our bullpen and making that final push into the Wild Card berth.