24. Jairo Díaz (261 points, 23 ballots)
Jairo Díaz is the forgotten man in the Rockies bullpen heading into the 2017. The fireballing 25-year-old right-handed reliever, who had contributed to the 2015 bullpen, unfortunately saw his season lost to Tommy John surgery in spring training. If he can come back healthy in 2017, he’s a dark horse to be a significant contributor to the bullpen for a Rockies team that could be in contention.
I like to tell the prospect story of Díaz while he’s still eligible for this list because it’s an example of why baseball is so wonderful. Díaz had a stellar 2014 that got him to the big leagues all the way from High-A ball. That’s unusual in itself, but the really crazy part is that all of this progress occurred after Díaz had spent several years with the Angels as a catcher! He signed with the organization in 2007 out of Venezuela behind the plate, but after two seasons in the Dominican Summer League trying and failing (.118 batting average in 2009) to hit professional pitching, Díaz moved to the other side of the battery in 2010 as a pitcher with a rocket arm.
Díaz didn’t make a stateside debut until his fourth professional season and didn’t arrive in High-A until his sixth—and then in his seventh season he jumped from High-A ball at the start all the way to the majors—in a division race!
In an abbreviated stint in the Show, he threw 5⅔ innings for the AL West-champion Angels, allowing two runs while striking out eight and walking three. Across the two minor league stops, Díaz hurled 64⅔ frames of 3.48 ERA ball while putting up an impressive 11.8 K/9 rate, combined with a respectable 2.8 BB/9. As such, Díaz appeared nearly fully formed when the Rockies traded Josh Rutledge to the Angels for him after the 2014 season, but that obscures the journey that got him to this point.
When Colorado acquired him, it was expected that Díaz would be in contention for a bullpen spot in 2015. Since Díaz had thrown just 32⅔ innings at the Double-A level in 2014 before his big league promotion the year prior, it wasn't surprising that initially he was sent to Triple-A Albuquerque to begin the season.
In 55 innings across 47 games for the Isotopes (against hitters on average that were three years older), Díaz struggled relative to his 2014 success. Specifically, though his 8.2 K/9 rate was acceptable, his 6.1 BB/9 rate certainly was not, nor was his 4.58/5.44/1.60 ERA/FIP/WHIP combo.
Nonetheless, the Rockies needed arms for the bullpen in late August and Díaz was there to answer the call. Just as he had in Los Angeles the year before, Díaz stepped his game up at the Major League level. Across 21 games, Díaz threw 19 innings of 2.37 ERA ball (3.56 FIP) while maintaining a 8.5 K/9 and reducing his BB/9 to 2.8. In those 21 appearances, Díaz allowed a run only three times, and in only one of those outings were there multiple earned runs allowed.
Díaz finished strong—his final outing of the year was a 1-2-3 eighth inning of a 3-2 game in which he struck out the side on 13 pitches in game 161 against the Giants.
From a stuff perspective, Díaz is a potential relief ace out of the pen if his command improves. From MLB.com, who placed Díaz 25th on their 2015 list of Rockies prospects:
Diaz arrived (from the Angels) with a plus plus fastball that rates at the top of the scale and automatically became one of the best heaters in the system. He'll sit 97-98 mph consistently and can hit triple digits. He combines it with a solid average slider that can miss bats when he's throwing it well. Diaz also has a below-average changeup that could give hitters another look, but he doesn't really need it much pitching in short relief. The biggest issue for Diaz has been his command and control ... If Diaz can get back to commanding the baseball consistently, he has the two-pitch power arsenal teams like to see coming out of the bullpen to close games at the highest level.
The way Díaz pitched down the stretch for the Rockies in 2015 is obviously an exciting what-if for the big league bullpen over the next few years, but the TJ surgery recovery and underlying struggles with command he had in Albuquerque in 2015 should mitigate the optimism.
Still, the golden arm and the great story make Díaz a personal favorite of mine—I placed him 21st on my personal ballot because I see Díaz as a high leverage reliever (40+ FV). Hopefully he’s not eligible for the next edition of this list because he’ll have played a key role in the Rockies’ bullpen.