Miami Marlins reliever David Phelps has been working as a setup man this season after spending a few years as a swingman. Since his rookie season in 2012, Phelps has appeared in 135 games, 59 of those as a starting pitcher. For his career, he has thrown 326.1 innings as a starter and 113 as a reliever. His 4.36 ERA as a starter is fine, but nothing special, as is his 3.50 ERA as a reliever. He was generally used as the long man out of the pen, pitching when the team was behind or ahead by a large margin or when the starting pitcher was forced to leave the game early.
Not this year, though. The Marlins have used Phelps as their setup man since the beginning of the season and the results have been extremely positive. In 28 innings pitched across 25 games, Phelps has a 3-3 record and a 1.93 ERA. He is striking out 10.93 batters per 9 innings and walking just 3.21. His previous career high K/9 was 8.67 in his rookie year. Being able to concentrate on just one inning, usually the eighth, has made Phelps better able to throw his pitches for strikes and gets swings and misses at a better rate than before.
The shortened outings and specified expectations have also allowed Phelps to put more into his fastball. He is averaging 93.3 mph on his fastball this season, with a peak of 96.2 mph. His career average fastball is just 90.6 mph on average, so there has been a significant jump. The fastest pitch he has thrown in his career came this season as well (the 96.2 mph fastball).
According to Fangraphs fWAR, this is already close to the best season of David Phelps’ career. He accumulated 1.1 fWAR in 2013, for now the best season of his career per the value stat. However, in 2016, he already has 1.0 fWAR and could surpass his 1.1 from 2013 as early as this week.
Always an effective, versatile, innings-eating type of pitcher, Phelps and the Marlins have been able to create an elite setup man, helping the team cope with the loss of Carter Capps for the season. With rookie Kyle Barraclough looking strong and closer A.J. Ramos starting the season off well, the back end of the Marlins bullpen has been a surprising strength for the team.