Koch could make a spot start Saturday against the Nationals, Jeremy Vernon of MLB.com reports.
The Diamondbacks called Koch up from Triple-A Reno prior to Thursday's game against the Reds, providing the team with another fresh arm after Taijuan Walker, the team's originally scheduled starter for that contest, was placed on the paternity list. Patrick Corbin, who had been in line to take the hill Saturday, was moved up in the schedule to start Thursday and provided the Diamondbacks with 7.1 quality innings while Koch went unused out of the bullpen in the victory. Since the Diamondbacks confirmed Zack Godley would start on normal rest in Friday's series opener and Walker isn't expected to be activated until Sunday, a void in the rotation still exists for Saturday. Thus, if Koch is again unneeded in relief Friday, he'll likely be the leading candidate to start Saturday, though he won't make for an attractive DFS or season-long streaming option in such a scenario. The right-hander has submitted an 8.47 ERA and 1.59 WHIP over 17 innings with Reno this season.