The Brewers drafted James Jacob Nelson in the second round of the 2010 MLB Draft. The University of Alabama product began his steady ascent through the minor league shortly thereafter, putting together solid numbers and making a short, four-game big league debut in September 2013. The 6'6", 245 lb hurler broke out in a big way in following season. In 17 games for the AAA Nashville Sounds in 2014, Jimmy posted a dominant 1.46 ERA in 111.0 inning pitched, striking out 114 batters against just 32 walks. He skyrocketed to the number one on the Brewers' top prospect list and was ranked as the 38th best prospect in all of baseball in Baseball America's 2014 Midseason Top 50.
The Brewers called Nelson up for good in July 2014. He faced some adversity during his first extended period in the big leagues and finished the season with a 4.93 ERA in 69.1 innings pitched. Some of his struggles could be attributed to a .344 BABIP and 66.6% strand rate, both significantly worse than the league average and Nelson's career average. His 3.78 FIP was more encouraging, as were his above average 48.8% ground ball rate and 3:1 K-BB ratio.
The Brewers traded Yovani Gallardo prior to the 2015 season in part to open up a full-time spot for Jimmy in the starting rotation. He responded by becoming the anchor of pitching staff, leading the Brewers with 30 starts and 177.1 innings pitched. He posted an 11-13 record and a 4.11 ERA, striking out 148 batters and walking 65. He did see a two percent increase in his walk rate, but he helped negate that by generating more swing strikes (10.0%), strikeouts (19.7%), and ground balls (50.6%). Nelson's FIP of 4.14 almost equally matched his ERA, and his 2.1 fWAR ranked as the highest on the Brewers and 32nd among the 393 pitchers that appeared in the National League this season.
According to Brooks Baseball, Nelson's repertoire on the mound includes a fastball, sinker, slider, curveball, and changeup. Jimmy's sinking fastball is his most heavily utilized pitch; it averaged 94.30 MPH in 2015 and he used it to generate worm burners 58% of the time it's put in play. His slider was among the best in the MLB this season, as opponents hit only .146 with a 21.21% whiff rate against it. Pitch F/X valued Jimmy's slider at 10.2 runs above average, tying for 11th best in the NL.
Perhaps his most important pitch is his curveball, which he didn't throw regularly prior to this season. Using a grip taught to him by minor league teammate Hiram Burgos, Nelson's curveball became a weapon used to effectively neutralize lefties (who hit just .196 off the pitch in 2015). The addition of a legitimate plus pitch seemingly out of nowhere raised Nelson's ceiling from that of a middle rotation starter to a potential front line starter, if he can continue to hone his control and keep his strikeout totals climbing (as Steamer projects him to do next season).
Nelson has now established himself as a legitimate starter in the big leagues and he showed several flashes of his dominant potential throughout 2015. He will turn 27 next season and has another five seasons of club control remaining, and at 1.107 days of service time will probably fall short of hitting the Super Two threshold. The Brewers haven't extended a starting pitcher since Gallardo's 5 year, $30.1 mil deal (with a $13 mil club option that increased to $14 mil when he was traded to Texas) prior to the 2010 season. However, given Nelson's standing as the club's top starter and the tantalizing potential that he has yet to tap into, he could be someone the Brewers may have interest in locking up long-term.
The two most recent examples of extensions for starting pitchers between one and two years of MLB service time are the deals signed by Jose Quintana of the White Sox and Julio Teheran of the Braves prior to the 2014 season. Quintana's five year, $21 mil deal offers an imperfect comp due to his meteoric rise from six year minor league free agent to front line starter after signing with the Sox. Quintana failed a drug test and bounced around with three organizations before breaking through with Chicago, so his decision to secure financial security when it was offered to him was a sensible one.
Teheran, on the other hand, was a highly touted prospect while he was coming up through the Braves' system. He made his big league debut in 2011 but didn't become a starter full-time until 2013, and he posted a 3.44 ERA/3.85 FIP and 2.5 fWAR in 211.2 big league innings prior to inking his extension. Teheran's deal was for six years and $32.4 mil (with a seventh year club option), though it too isn't a perfect comp; Teheran made his debut in Atlanta at the tender age of 20 and guaranteed portion of his deal covers his age 22-28 seasons.
Given that Jimmy Nelson didn't become a full-time big leaguer until the age of 26, the Brewers are in control his rights through his age 31 season. A six year extension would buy out his remaining years of club control and one year of free agency, while still allowing him to hit the open market prior following his age 32 season in hopes of a second multi-year deal. I'd personally be wary of extending him (or anyone) beyond that, given how players tend to regress as they age through their 30s.
Then there's the matter of money. Nelson's platform of a 4.21 ERA/3.97 FIP and 3.2 fWAR in 236.2 innings isn't quite as strong as Teheran's or Madison Bumgarner's (who's five year, $35 mil extension inked at the start of 2012 still stands as the record for a pitcher with one to two years of service time) when their deals were consummated, but big league contracts have also seen a good deal of inflation in recent seasons. In my opinion Nelson therefore wouldn't be out of line asking for a $7 mil average annual value, which would bring the total commitment over a six year time frame to $42 mil.
That figure would represent a new record high guarantee for a pitcher with between one and two years of MLB service time and offer Jimmy enough financial peace-of-mind for a lifetime. It would also give the Brewers cost certainty over a player who may very well be at the front their rotation for the foreseeable future. Even if Jimmy doesn't get any better than he is right now, he'd only really have to accrue between 5-6 WAR (factoring one WAR as roughly $7-8 mil) over the life of his deal to justify a $42 mil expenditure.
There's always an inherent risk when handing out guaranteed contracts to a pitcher, of course; one can never quite know how many innings an arm has in it before it starts breaking down. Nelson's big body and track record of durability bode well for him holding up over the long term, however, and his pitching profile leads me to believe that he will continue to improve in the coming seasons. That could make extending Jimmy a gamble worth taking for the Brewers.