Hessler was a 28th-round selection for us in the 2010 draft, so the "Who?" question is clearly not a new one. However, this is not a team record: most famously, we got All-Star Junior Spivey in the 36th round of the 1996 draft. Still, players chosen that late, typically do not make the majors, or if they do, don't produce much. The last 28th round pick to put up positive bWAR was, coincidentally, another AZ choice, Evan Scribner in 2007. It'll be interesting to see what Scribner does; unlike some roster moves, this is not a temporary injury filler, it's more like an audition for a permanent role (even if Oliver Perez has expressed interest in returning here when he hits free agency).
Hessler moved slowly through the farm system for his first four years. He spent almost all of 2014 in High-A with Visalia, except for a single emergency start for the AAA Aces. His ERA was nothing special, at 4.33 over 62.1 innings in total, but he struck out 82 for a K-rate of 11.8 per nine IP. That got him a promotion to Mobile after ten games for Visalian at the start of this season, and the numbers there were even more impressive. Over 13 appearances and 15.1 innings, he allowed just one earned run, for an 0.59 ERA, with a K:BB ratio of 19:4, holding opposing hitters to a .173 average, getting another promotion to Reno.
His first game there didn't go too well, as he retired one of five batters faced, the other four all scoring, and after a couple of weeks, he was sent back to Mobile. However, he continued to dominate hitters there - 10 innings, one earned run, a K:BB of 13:1 - and another shot in Reno resulted. This has also been a little shaky - K:BB of 3:3 in his six games out of the Aces bullpen. But it seems the team still likes what they see in Hessler, and it may simply be the case that the heavy slider which is his trademark pitch is just not as effective in the thin air of Reno
Looking at his splits, there isn't much difference - lefties have an OPS of .521 against him this year at all levels, righties a .544. We'll see if Chip Hale uses him as a LOOGY like his predecessor, who only had 19 of 48 appearances this year in which Perez retired more than one batter. When he appears, Hessler will become the 42nd player and 24th pitcher used by the Diamondbacks this season. The 26-year-old will be the eighth player to make his major-league debut with Arizona in 2015, and the fifth pitcher, after Archie Bradley, Enrique Burgos, Zack Godley and A.J. Schugel. No word yet of a number for Keith.
Good luck to him, especially if he gets to make his debut this afternoon in front of a packed house at Chase Field, honoring Randy Johnson. It's still the same game: just keep telling yourself that, Keith!