Keynan Middleton was supposed to be the Angels’ closer of the future. So you can imagine that it was pretty disappointing when he went down with Tommy John surgery, and even more disappointing when he came back as a shell of the pitcher he was before. The Angels, apparently, didn’t consider it a priority to bring him back to their middling bullpen, which isn’t exactly something that speaks well to Middleton. Perhaps, then, the Mariners may have seen something that they could unlock.
For me, I saw a few different things. I took a bit of a leap in December when I wrote that Middleton not only could use an adjustment in pitch mix, but also that his slider could use a little tweaking.