Koch will remain in the Diamondbacks' rotation, Steve Gilbert of MLB.com reports.
Koch started for the first time this season Friday in place of Taijuan Walker. With Walker out for the season after undergoing Tommy John surgery, a permanent rotation spot has been opened up in Arizona, at least until Shelby Miller returns from his own Tommy John surgery sometime this summer. Koch has a 2.77 career ERA in 26 big-league innings, though his 4.64 xFIP indicates that he's nothing special.