One of the best rookie relievers this year is Tommy Kahnle of the Colorado Rockies. A Rule 5 pick during the winter meetings last December, he's established himself as a key part of the Rockies staff, transitioning from relatively unheralded prospect to a firm middle relief spot. Can Kahnle take on a larger role going forward?
Kahnle was used as a starter in college, pitching for Lynn University in Florida, a strong Division II program. Although he went 2-7, 5.06 in 75 innings in 2010 (71/47 K/BB), he was still drafted in the fourth round due to his arm strength. The Yankees moved him to the bullpen and he took well to the switch, posting a 25/5 K/BB in 16 innings for Staten Island in the New York-Penn League that summer.
For Low-A Charleston in 2011, he posted a 4.22 ERA in 81 innings but with a 112/49 K/BB and 69 hits allowed. He needed better control, but the K/IP ratio and the low hit rates pointed to upside. He ran up a 2.45 ERA in 55 innings for High-A Tampa in 2012 with an improved 72/24 K/BB.
Kahnle was with Double-A Trenton last year and posted a 2.85 ERA in 60 innings, collecting 15 saves with a 74/45 K/BB and 38 hits allowed. His K/IP and H/IP marks remained excellent, but the walk rate was still quite high. The Yankees did not protect him on the 40-man roster and the Rockies snagged him in Rule 5.
As you know, he stuck on the roster and has performed well so far: 2.80 ERA in 55 innings with a 44/24 K/BB and 35 hits allowed. This is very much in line with his minor league performance. He's tough to hit, although the walk rate is still high enough that his components aren't as good as the ERA, with a 3.80 FIP. That's been the pattern for most of his career.
Kahnle's fastball averages 95 MPH and has been clocked as high as 98. He'll mix in a slider, a changeup, and occasional slower curves. Stuff has never been the problem: it has always been a matter of command, but he's made substantial progress in that department, cutting his walk rate almost in half this year.
If Kahnle can sharpen up his command just a bit more and get his components more in line with the ERA, he could be the heir apparent to 41-year-old LaTroy Hawkins as the closer. All in all, he was quite a find in Rule 5.