According to beat writer Andy McCullough, the Mets are possibly going to use Darin Gorski as a LOOGY (lefty specialist) for the Major League team in 2013 (after getting added to the 40 man to be protected from the Rule 5 draft). Gorski, 25 years old, was drafted in the 7th round in 2009 out of college. He has impressive size at 6-4 210 and pitched in AA for the entire season. I assume that Gorski would have to compete with Danny Herrera (coming off Tommy John, probably won't be ready for the start of 2013) and Tim Byrdak (also coming off injury, is on minor league deal). While this would make maintaining the job difficult, it should make it easy to get the job initially.
Gorski made 24 starts (and 1 relief appearance) with the AA club where he was about league average when it came to age, and had a FIP .59 worse than league average but SIERA .03 better than league average. The home run problem was mainly on the road (1.52 HR/9IP) as the Mets' AA home park is pitcher friendly (95 one year park factor in a league that gives up .75 HR/9IP), but he also gave up more than a homer per 9 innings at home. His measly 30.8 GB % didn't help, as his HR/9IP was 12.9 %, high but not so much that you assume that it is fluky (and his HR/FB % was higher than league average in A+ in 2011 as well). He also had .9 HR/9IP in 2009 and 2010, in leagues that had averages of .4 HR/9IP and .6 HR/9IP respectively. It is clear that he has a home run problem and doesn't exactly keep the ball on the ground, but there is some good news statistically. He had exactly a league average walk rate along with a strikeout rate 1.4% better than league average in 2012.
The Mets probably want to use him as a LOOGY because of his large platoon splits. Over the last two years, Gorski has a 3.04 FIP and 3.76 SIERA against lefties, with a FIP near 5 against right-handed hitters. His home run problem doesn't exist against lefties and he actually has a decent ground-ball rate against them. The problem is, those numbers are not exactly dominant. Herrera has a career 3.38 FIP and 3.63 xFIP against lefties in his career, while Byrdak has a 3.50 FIP and 3.58 xFIP in his career. Obviously Gorski's numbers are a little better against lefties and he was a starter in the minors, but would the positive regression of the move to the bullpen outweigh (or at least be about the same) the general regression from AA to the Majors? I am not sure how to weigh that statistically, so lets look at his stuff and a scouting report.
John Sickels describes Gorski as a pitcher with "superior command of average fastball and off-speed stuff, refined changeup". He sits around 88-91 MPH with his fastball most of the time. He also throws a slider that is in the low 80s like his changeup and mixes in a two-seamer as well. His fastball is pretty straight and mostly high, so I can definitely see why it won't get right-handed hitters out in the Majors. He tries to locate it both inside and outside to righties, but I am still skeptical.
Evidently his delivery and mechanics improved after the 2010 season. He doesn't have much of a leg stride, instead having just a high leg kick. He also brings his arm and the ball behind him, giving him some decent deception. He doesn't have any kind of sidearm motion that you usually see in LOOGYs. It still is a delivery that seems to work a little better against lefties than righties. Honestly, I wasn't overly impressed with his changeup. He clearly looks like a strike thrower, so I don't think there will be control problems in a Major League 'pen.
It seems that the Mets have two choices with Gorski. They can convert him to a reliever and see how he does against lefties in spring training/early in the season in the MLB, or they can try him out as a starter in AAA. The latter option would be in an effort to see if he could latch on as a capable (but certainly below average, most likely a 5 in that terminology) starter in 2014. The Mets' pitching staff was worse against lefties than righties in 2012, and their best returning relievers against lefties were Bobby Parnell and Tim Byrdak. Brydak may not be ready for the start of 2013 and Parnell isn't really used as a LOOGY, pitching in more high leverage situations. Having Gorski in the Majors would help them avoid signing a free agent and I am not sure he would stick as a starter anyway.