The Diamondbacks recalled Koch from Triple-A Reno on Tuesday, Nick Piecoro of The Arizona Republic reports.
Koch was optioned to Reno on March 22 but returns to Arizona with third baseman Jake Lamb (shoulder) heading to the disabled list. The 27-year-old brings immediate value to the Diamondbacks' bullpen in desperate need of depth following Monday's 15-inning win over the Dodgers. Koch should typically be utilized in a low-leverage role while he remains in the majors.