In a move many of us thought should have happened at the onset of the season, Kris Medlen will be a starter in Atlanta this season. He was sent to AAA to get stretched out over a span of 2-3 weeks and then step into the rotation. There is no word on who will be replaced, though the two likely candidates are Mike Minor and Randall Delgado. This will be Medlen’s second go-round as a starter after showing mixed results the first time.
In 2010, in a matter very similar to this year, he made 12 relief appearances before starting 14 games, with a bit of relief work surrounding the All-Star break. As expected, Medlen was better out of the bullpen, allowing a .244/.287/.307 slashline and a 3.04 ERA, compared to a .265/.312/.449 line and 3.86 ERA as a starter. Walks were not a problem, showing similar rates in each role. Strikeouts dipped a bit, from 22% to 18%, but home runs were the biggest problem. He maintained similar flyball rates in each role, but the percentage of those flyballs going out of the park tripled as a starter. While the sample size for his relief outings (95 batters faced) is not very big, this is a very big difference.
Part of the HR problem could be his mediocre fastball. In relief, he was able to average 91 MPH, but his velocity dropped 1 MPH as a starter. This does not seem like much, but he threw a straight-ish two-seamer and a flat four-seamer, making velocity much more important. His stuff has not changed much from two years ago, though he has replaced the four-seamer with an iffy cutter. He has also kept the ball in the park so far, allowing one HR in 28.1 IP, but his K rate is only 15% and likely to go down as a starter.
The other concern is how his arm holds up. Medlen’s 2010 season ended in early August, after needing to undergo TJ surgery. He has never exceeded 120 IP in a season at any level, and some wonder if he can hold up starting an entire season. If he makes three starts or so in the minors, say 4, 5, and 6 innings, that will put him at 43 IP for the season. After that, he should get 15-16 starts in Atlanta, giving him around 90 more innings to push over the 120 mark. As a small pitcher (5’10”, 190), Medlen gets the standard durability doubts, though there is no evidence such a correlation exists. That isn’t to say he won’t get hurt, but he should not be any more likely to do so.
Overall, I suspect Medlen will put up rates similar to Beachy except a few less strikeouts. Beachy has a 3.18 FIP and a 3.98 xFIP, so Medlen would probably end up with an ERA around 4.00-4.20, good for about 1 WAR over the second half of the season. While that is about league average, it is much better than Minor and Jair Jurrjens so far and a slight improvement over Delgado, making it a good move by the Braves.