Haley, 28, appeared in 10 games with the 2017 Twins as a Rule 5 pick before he was returned to the Red Sox. He was selected to the Red Sox’ roster a year later in 2018 but pitched in only four games at the MLB level before being outrighted off the 40-man roster at season’s end. In the offseason, he opted to sign with the Samsung Lions of the Korea Baseball Organization rather than pursue a minor league contract with an MLB organization. Things didn’t go well for Haley in the hitter-friendly KBO. He made 19 starts there and was tagged for a 5.75 ERA with 84 strikeouts and 34 walks in 87 2/3 innings of work before being cut loose (somewhat ironically, in order to open roster space for former Giants outfielder Mac Williamson to sign with the Lions).
That may all be a relatively unappealing profile at first glance, but Haley has a strong track record in Triple-A, where he’s pitched to a 3.53 with 7.6 K/9 against 2.4 BB/9 in 260 1/3 innings across parts of three seasons (47 starts, two relief outings). He’s typically posted average or better ground-ball tendencies and has limited home runs fairly well, surrendering an average of 0.97 long balls per nine innings pitched.