Justin Dunn has been on the radar since before he was acquired by the Seattle Mariners as part of the now-famous Edwin Diaz for Jarred Kelenic trade. During his junior season at Boston College, speculation led many to believe that the athletic righty was the Mariner’s preferred choice with the first draft selection of the Jerry Dipoto era. But after Kyle Lewis somewhat shockingly fell to Seattle at pick 11, Dunn would go to the Mets just a few picks later.
But Dipoto kept close tabs on Dunn and jumped at the chance to acquire him. After a promising 2019 season in AA, Dunn got his first cup of coffee in the big leagues, but his 5.2 innings in 2019 hardly left much room for analysis. But Dunn has made all but one of his scheduled starts in 2020 and the negative has far outweighed the negative.
The biggest concern with Dunn thus far is his total lack of control in most of his starts. Dunn has walked a staggering 38 batters in 47.1 innings while posting just 41 strikeouts. The nearly 1:1 K/BB ratio is unacceptable and a bit odd. Dunn is a good athlete with simple delivery. But the numbers speak for themselves.
Dunn has also seen a slight drop in his average fastball velocity. Dunn was billed as a guy whos sat 91-94 as a starter, but in 2020, his average is down 1.5 MPH to 91.2 MPH. Dunn has sat comfortably at 88-90 for most of 2020 and has only touched 93 MPH a handful of times. This could be a deliberate change to try and improve his control, but without knowing for sure, it is a slight cause for concern.
Dunn’s 2020 is uneven by any stretch. Unlike Yusei Kikuchi, Dunn has actually been worse than his ERA indicates. Dunn’s 4.20 ERA is a good number, especially for a rookie starter. But his 6.25 FIP and 6.42 BB/9 and his 92.3 MPH average exit velocity all paint a troubling picture. Dunn has also been using a curveball as his primary breaking ball, putting off throwing the slider, the better of his two pitches.
Dunn’s future could very well be in the Mariners bullpen, but at 91 MPH with a mediocre curveball and average slider, he isn’t much use to anybody. But a quicker delivery could see the fastball jump back up into the mid-to-upper 90s, where he was at BC, and make the slider more effective in shorter stints. Dunn doesn’t need to move to the bullpen now, but he shouldn’t be guaranteed a rotation spot in 2021. A long stint in the minors could be called for and may ultimately be the best move for Dunn and the Mariners alike.