The Emergence of David Phelps
Every year, there are countless quality performances in baseball that go unnoticed. Also every year, a number of unexpected performers step up and provide value that no one expected. One player that could fall into both of those camps is David Phelps of the Miami Marlins. Phelps quietly had a strong year during his second season in Miami, and could be in line for a prominent role on the Marlins in 2017 and beyond.
Phelps was drafted by the Yankees back in 2008 in the fourteenth round after a three year career at Notre Dame. He was never much of a prospect, but played well across his minor league stops, logging a 2.53 ERA almost exclusively as a starter in the minors from 2008 to 2012. He earned his major league debut with the Yankees in 2012 at age-25, and had a quality rookie season. He maintained a 3.34 ERA in 99.2 innings in a swingman role for New York.
Despite his early success, Phelps faded mostly into anonymity from there, providing close to replacement level work for the Yankees in 2013 and 2014. After posting a 4.63 ERA across those two seasons, the Yankees made him essentially a throw-in in the deal that sent Martin Prado to Miami in exchange for the young fire-baller Nathan Eovaldi.
2015 was more of the same for Phelps. The Marlins worked him primarily as a starter, but the success that he found as a rookie continued to elude him. Across 23 appearances, 19 of them starts, Phelps logged 112 innings and a 4.50 ERA with 77 strikeouts compared to 33 walks. All told, Phelps’ 2013 to 2015 seasons amounted to 0.1 rWAR and an 84 ERA+.
Phelps did possess a decent 4.10 FIP over that span, as he generally owned fine strikeout-to-walk figures and was able to limit home runs. Still, that wasn’t enough to really make Phelps stand out as a breakout candidate in 2016, as he profiled as just another back of the bullpen arm who could fill mop-up duty and make the occasional start in a pinch.
However, something seemed to click for Phelps in 2016. The raw numbers themselves are impressive enough on their own: 86.2 innings and a 2.28 ERA, good for a 172 ERA+. He ranked fifth in MLB in adjusted ERA among pitchers with at least 80 innings. He struck out 114 batters and walked 38. When he was on the mound in 2016, Phelps was shockingly dominant.
This was a startling break from norm. Never before had Phelps struck out more than a batter an inning, and prior to 2016, his career SO/9 was 7.5. He struck out nearly 12 batters per nine in 2016. He gave up only six home runs in 2016, and benefited from a career-low .286 BABIP, but neither figure is nearly extreme enough to make it seem as though Phelps had simply lucked his way into a career-best year.
Instead, a mid-career velocity spike looks like the probable culprit for Phelps’ breakout. Entering 2016, Phelps was never a hard-thrower. His average fastball velocity, according to Brooks Baseball, was 91.42 mph over his first four years in the majors. His velocity never really wavered much when Phelps switched between starting and relief roles. Phelps’ lowest velocity over the course of a month from 2012 to 2015 was 90.58 mph, and his highest such velocity was 92.43 mph.
The average velocity on Phelps’ fastball in 2016 was 94.62 mph. His cutter velocity also ballooned from 88.4 mph in 2015 to 90.81 mph in 2016, and the effects were stark. After generating a whiff on just 16% of swings on his four-seamer prior to 2016, Phelps generated a whiff on 28% of swings on his fastball in 2016. The line drive and fly ball rates against his fastball fell. Overall, opposing hitters batted just .160 with a .302 slugging against Phelps’ heater in 2016.
His bump in velocity seemed to help his other pitches too. After yielding a .294 average and .475 slugging against his sinker prior to 2016, Phelps held hitters to just a .173 average and .200 slugging with his sinker. Likewise, batters hit just .216 against his curve after hitting .266 prior to 2016. Most likely, Phelps’ added firepower gave hitters less time to react to all of his pitches, increasing the effectiveness of his entire repertoire.
Whether or not Phelps can sustain this jump in ability probably will determine whether Phelps can turn a career year into full-on career turnaround. Phelps’ velocity did decline a bit as the year wore on, but only slightly, as his 95.21 fastball velocity in May fell a bit to 94.74 mph by the final month of the season. Most encouragingly, Phelps shifted from the bullpen to the rotation in August and didn’t sustain a large drop in velocity. Over five August starts, Phelps’ average fastball speed was never lower than 94 mph and topped out just above 95 mph. That Phelps was still throwing gas even as a starter bodes well for his ability to maintain this velocity jump in the future, if he is a reliever or a starter.
However, Phelps may have the most upside should the Marlins leave him in the rotation. His stuff did not play down during his brief return to starting, and his overall numbers in those five starts look great (small sample size caveats apply). In 2016, Phelps allowed a paltry .203/.292/.297 slash line as a reliever, and an even more meager .184/.276/.287 slash line as a starter. He had a 2.22 ERA during those five starts, and struck out 32 batters while walking just 10. If Phelps were to make 25 to 30 starts over the course of a season, he would almost certainly not maintain that level of performance, but the fact that his numbers and velocity held strong during a brief rotation stint means starting him is probably worth a shot.
Plus, Phelps is under team control for three more seasons, and can shift right back to the swingman role he’s succeeded in should starting prove to be less than optimal. With plenty of team control left and a breakout season behind him, Phelps looks like a very interesting asset that the Marlins have stumbled on. Of course, the Marlins are known for flipping assets once they become more valuable, so if Phelps continues to break out, he may not be in Miami for much longer. But given his clear change in skills last season, Phelps is a little-known player to look out for going forward.