Dan Jennings

Jennings pitched effectively in 62.2 innings of relief for the White Sox and Rays, putting up a 3.45 ERA. His 4.72 FIP suggests his ERA ought to have been a good deal higher, but his career ERA has beaten his FIP by 87 points over 279.2 innings, so perhaps he is a rare FIP-beater. He keeps the ball on the ground (59.8 percent last year), which helps him to mostly overcome poor strikeout (19.1 percent) and walk (11.6 percent) rates. It's very much a middle-relief profile, which should leave Jennings with little chance of building on the one career save he's recorded so far. That limits Jennings' value in most fantasy leagues.

In his first season exclusively at the MLB level, Jennings had a solid year out of the White Sox bullpen. Although his WHIP remained the same at a very pedestrian 1.40, the left-hander posted a stellar 2.08 ERA. This success was possible due to an outstanding 0.2 HR/9 over the course of the season. Although things seem to be looking great for Jennings, these results will be difficult to replicate given his other numbers. His already-low strikeout rate dipped even further, his BB/9 ascended to 4.2, and his FIP sat at 3.43. To add insult to injury, the reliever's average fastball velocity (90.8 mph) also dropped by nearly two miles per hour from 2015. He made things work in 2016, but look for significant regression this season, as he will be fortunate to hold onto a low-leverage role for the entirety of 2017.

The White Sox picked up Jennings from the Marlins in the 2014 offseason in exchange for Andre Rienzo, and Jennings quickly became one of the team’s more frequently-used relievers despite average, hittable stuff. His ERA rose from 1.34 to nearly 4.00 over the course of the year, but his FIP was constantly hovering around 3.47. He should occupy a middle relief role once again in 2016.

Jennings spent the majority of the 2014 season with the major league club, ultimately posting a sparkling 1.34 ERA but with an unsightly 1.54  WHIP over 40.1 innings pitched with the Marlins. He benefited from an unsustainable 94.9% strand rate while dancing in and out of trouble with regularity. Jennings has solid strikeout ability, racking up nearly a strikeout per inning over the past two seasons, but continues to struggle with walks. The left-hander has yet to be truly tested in a late-inning role and Jennings seems unlikely to be tried there unless he can prove more consistent with his command.

Jennings chipped in 40.2 relief innings out of the Marlins' bullpen in 2013 on his way to a 2-4 record with a 3.76 ERA. The righty did an excellent job of keeping the ball in the park, allowing just one homer run in 47 appearances, and while striking out nearly a batter per inning (8.4 K/9). Primarily viewed as a middle reliever, Jennings failed to find himself in too many high-leverage situations and collected just one hold during his sophomore season. While he'll likely be an important piece in the Miami bullpen once again, it is difficult to expect much of an impact on the box score while throwing in middle relief.

Jennings posted a strong 1.89 ERA in 19.0 innings pitched for the Marlins in 2012, but struggled with wildness, walking 11 batters during that sample. The lefty hurler, who tosses a fastball in the low-90s complemented by a slider and the occasional changeup, ended his first trip around the big leagues with a poor 1.53 WHIP. Prior to his callup, Jennings had made notable progress in limiting the walks, issuing just 16 free passes over 51.2 innings pitched (2.8 BB/9) in Triple-A after walking 4.5 BB/9 in 2011 and the Marlins remain hopeful that he'll eventually display improved control with more experience in the majors.