Seattle Mariners: Evaluating the prospects in the Cano deal

A relief convert

Before his draft season with Boston College, Justin Dunn had started just 7 of his 27 collegiate appearances. Even in his draft season, Dunn made just 8 starts out of 18 appearances, which led to his dominant stuff being a significant point of debate in pre-draft rankings for many teams. Some teams liked him in the first round, and other teams were out until the third round at least.

The Mets drafted Dunn 19th overall, and he came out and showed very well in the New York-Penn League in his draft season, with a 1.50 ERA and 35 strikeouts over 30 innings.

He was pushed up to high-A St. Lucie in the Florida State League in 2017, and he struggled with nagging injuries and general control issues throughout the season, with a 5.00 ERA and 1.56 WHIP over 95 1/3 innings, but with an 11.1% walk rate and just a 17.3% strikeout rate.

Dunn worked with the Mets in the offseason before 2018 to clean up his delivery, and the results were excellent. Dunn’s mid-90s fastball was able to locate much better, which allowed for its natural sink to really play up. His improved location also allowed his plus slider and average change to play up significantly as well.

On the 2018 season, Dunn made it up to AA, totaling 135 1/3 innings, with a 3.59 ERA, 1.33 WHIP, and a 52/156 BB/K. He’ll likely open in AA again but move quickly to AAA when the Mariners feel he’s ready, and he could even see a little time at the big league level in September.