The Miami Marlins were short a starter late last season and were in the periphery of the playoff race. The Fish front office made a calculated move that was not well-regarded at the time, trading top prospect Colin Moran, the sixth pick of the 2013 draft, and former prospect Jake Marisnick for Jarred Cosart and the later traded Enrique Hernandez. The Marlins felt they needed starting pitching with injuries affecting two-fifths of their projected rotation at the start of the year, and Cosart is team-controlled for a very long time. The club bet on Cosart over Moran, and at least for 10 starts in 2014, the Marlins looked like they were right.
Cosart played well for the Fish last year, but he still displayed a lot of the problems he had with the Houston Astros and in the minors before that. Can he shore up these issues in 2015 and become a contributor?
1. Jose Fernandez
2. Henderson Alvarez
3. Mat Latos
4. Jarred Cosart
5. Dan Haren
Additional Depth: Tom Koehler, Brad Hand, David Phelps, Aaron Crow
Minor League Depth: Justin Nicolino, Jose Urena, Adam Conley
The story on Cosart has always been his struggles with walks, a lack of strikeouts, his excellent ground ball rates, and his high-velocity sinker. In many respects, this profile fits very well with a recently-traded Marlins starter in Nathan Eovaldi, another pitcher who once struggled with mediocre strikeout and walk rates. Where Eovadi was dealt because of a poor ERA last year, Cosart was lauded because he posted a 2.39 ERA and 3.32 FIP in 10 starts and 64 innings for the Fish last season. That gave Miami even more confidence that they had spotted a solid contributor, and that was enough to allow them to choose five years of Cosart over three years of Eovaldi.
Cosart did a few things well when coming to Miami. He upped his strike zone rate from 47 percent to 51 percent with Miami, conforming to the team's style of pounding the strike zone and depending more on balls in play. Cosart worked in the zone more often and that resulted in a drop in walks down to 8.5 percent with the Fish. You can see the difference when comparing the strike zones from before and after Miami.
You can see more pitches hitting the bottom of the zone and avoiding the area below that more often. He also worked a bit more high in the strike zone, where one would traditionally get more strikeouts. That did not seem to bump his strikeout rate, but hitters did make less contact both in and out of the strike zone on Cosart in Miami. Those improvements could be telling for solid future performance.
Still, when you break down the pre- and post-Miami starts, you can see that the differences are not as major as you would expect.
Cosart's improvement in walks was superb, but a lot of the difference in his ERA could be attributed to lower BABIP rates and a decrease in home runs. That decrease in homers may continue in Miami, but probably not to the same degree as we saw late last season. The more predictive ERA retrodictors like xFIP and SIERA, which try to determine what a pitcher with that statistical profile should get for his ERA, show that Cosart pitched like a 4.00 ERA starter in Miami.
Photo by Tommy Gilligan, USA TODAY Sports
Most of the systems expect some improvement in Cosart's strikeout rates, but the walk rates still look not promising. However, knowing Miami's prowess for coaching to the strike zone and encouraging contact, there is at least a decent chance that Cosart will work more in the zone than he did in the past in Houston. If he does do that, he could maintain closer to acceptable walk rates. Combine that with his strong mid-90's two-seamer and you have the recipe for a potential Henderson Alvarez-lite situation.
Of course, Alvarez himself is not projected to be great in 2015, so a lighter version of him may not be a strong player this season either. Alvarez was pegged for just over two wins in 170 innings of work, so we can be fairly sure that Cosart would produce less than that for Miami. Last year was the first full year Cosart played in the majors, but his innings counts have all been strong before that. It would not be unreasonable to expect 170 innings from Cosart in 2015 as well, provided he remains on the field and performing well.
Given the numbers above, we get an average expected ERA of 3.95 for Cosart. In 170 innings, that would be worth 1.8 wins for the Marlins. As expected, Cosart would not be an average player for the Fish in 2015, but at the same time, near-league average production is nothing to scoff at. If Cosart can continue to pound the ground and the zone more next year, one could even see some improvement. Rest assured, he will likely never reach a 2.32 ERA again for the Fish, simply because his ceiling with this skillset is so limited. However, Cosart could remain a decent contributor for Miami at least for next season.