Earlier today, the Diamondbacks traded for Brad Ziegler again. Hours later, they complete the one and most glaring need on the roster that they can fix by adding a solid LH arm for the bullpen in Jake Diekman. Diekman pitched the 9th inning of last night’s game against the Dbacks and sliced through the middle of the Dbacks order. On the season as a whole, Diekman has pitched to a 3.69 ERA in 39 innings with a K/BB of 48/23.
The main domino effect is that allows the Dbacks to pick and choose their spots to utilize Andrew Chafin, a reliever who’s putting up solid numbers unless asked to come into games with runners on base. Diekman can fill the high-leverage lefty role while Chafin can have more situations starting with a clean slate. In addition to allowing the Dbacks to use Chafin in situations that are better suited for him, it also allows them to finally jettison Jorge De La Rosa off the roster since they aren’t carrying 4 lefties in that bullpen. With Diekman, Chafin, and long reliever T.J. McFarland in the pen and all three of them meaningful pieces down the stretch, JDLR is as good as gone.
Going to the Rangers will be reliever prospect Wei-Chieh Huang. Huang moved to the pen mostly due to concerns about his ability to add weight to his frame and the stuff holding up. After a couple years of getting used to the role, he really has produced this year with a 2.39 ERA with a 78/23 K/BB ratio in 58 1⁄3 innings between Visalia and Jackson. The numbers were so eye-popping that I put him on my list of consequential reliever prospects and 2nd behind Yoan Lopez. I thought of Huang as a possible bridge reliever who could fill the gap between the starter and the back-end of the pen in both the regular season and especially the postseason with a plus fastball and curveball combination.
The end result is the Diamondbacks pick up a needed piece, as Diekman is a major upgrade over the replacement level JDLR as the 3rd lefty in the pen along with Chafin and McFarland. It cost the team a decent reliever prospect to land Diekman, who will be a free agent after the season. Diekman should be able report to the club today given that his previous team is already in Phoenix.