Not a Rookie: Mat Latos
Mat Latos was an 11th round pick in the 2006 draft, out of high school in Coconut Creek, Florida. His draft position was deceptive: he was considered a first round candidate on talent alone, but fell down draft boards because of excessive bonus demands, a University of Oklahoma commitment, and worries about his makeup and personality.
He didn't sign right away, but passed up four-year college baseball to attend Broward Community College in Florida and keep his options open. A good spring in 2007 convinced the Padres that he was worth the money, and he signed for $1.25 million hours before he would have re-entered the draft pool.
Latos made his pro debut in the Northwest League, posting a 3.83 ERA with a 74/22 K/BB in 56 innings for Eugene. He showed a 93-97 MPH heater in his debut, along with a plus slider. His curveball and changeup needed some work and his command was inconsistent, but his upside was clearly very high. I gave him a Grade B in the 2008 book, writing that he had the ceiling of a number one starter but that we needed to see some higher-level data.
Latos had health problems in 2008, missing much of the season with a strained oblique and a sore shoulder. He pitched well when healthy, seeing action for the Arizona League Padres, Eugene again, and Fort Wayne in the Midwest League, combining for a 2.57 ERA with a 69/13 K/BB in 56 innings. Scouts reported continued progress with fastball and breaking ball command, as well as an improved changeup. I gave him another Grade B in the 2009 book, writing that if he stayed healthy he'd be one of the best pitching prospects in the game.
Latos began 2009 back with Fort Wayne, but was promoted after posting a 0.36 ERA with a 27/3 K/BB in 25 innings. Moved up to Double-A San Antonio, he dominated the Texas League with a 5-1, 1.91 mark and a 46/9 K/BB ratio in 47 innings, allowing 32 hits. The Padres promoted him to the majors at that point and he held his own, going 4-5, 4.62 in 10 starts, with a 39/23 K/BB in 50.2 innings, allowing 43 hits, moving just barely past the rookie innings limit.
Overall in his minor league career, Latos went 12-8, 2.49 with a 216/47 K/BB in 185 innings, allowing 149 hits. That's outstanding: K/BB, K/IP, H/IP, all terrific, FIPS excellent, everything was as good as it could be sabermetrically.
His major league statistics weren't quite as good: his K/IP dropped from 8.8 at San Antonio to 6.9 in San Diego, while his walk rate jumped from 1.7 to 4.1. I think that's just normal adjustment: keep in mind that he was just 21 last year. If he had attended college at Oklahoma, 2009 would have been his draft year. If a guy jumped directly from college to the majors and posted these numbers in 51 innings, everyone would be drooling over him.
Looking at his Fangraphs and Pitch/fX data, his fastball and slider both rate as above average pitches by their metrics, with only the changeup coming out as a below average pitch. He relied mainly on his heater, throwing the fastball an estimated 66% of the time, with the slider at 20.5% and the changeup at 11.6%. That seems to jive well with the minor league scouting reports. The heater averaged 94 MPH and was clocked as high as 98. Again, this meshes perfectly with what he did in the minors. His stuff is clearly first class, though improving the changeup and sharpening his command are necessary steps for him to live up to his ace potential.
There are two worries with Latos: his makeup, and his health. Latos has an, um, unusual personality. The positive spin is that he's a free-spirit. The negative spin is best expressed by this quote from the 2009 Baseball America Prospect Handbook: "He tends to reject structure, lacks a commitment to improve and rubs teammates the wrong way with his flippant attitude." Descriptions I heard from informed observers in 2008 ranged from "he's just a different guy" to "what a jackass." His personality seemed to settle down in 2009, and he didn't look out of place on the major league diamond. Indeed, he has a strong mound presence. You don't have to be a choir boy to be a successful major league player, and at this point I'm not overly concerned about the makeup issue.
I am worried about his arm. He lost much of 2008 with the shoulder and oblique issues, and shoulder stuff always worries me. I also think his delivery looks awkward, to my eye anyway, like it puts stress on his elbow and shoulder. Other people, including some experts who know more about pitching mechanics than I do, disagree about this, but every time I see him pitch I think "he's gonna get hurt." Your mileage may vary.
In any event, if Latos does stay healthy, I think he has the natural ability to be a number one or number two starter. If he'd come in under the 50-inning limit, I'd rate him as a Grade A- prospect and would have put him at number four on my Top 50 pitcher's list.