Clarke will be called up from Triple-A Reno to start Saturday against the Giants, Zach Buchanan of The Athletic reports.
The Diamondbacks moved Zack Godley back to the bullpen once again, prompting the need for an additional starter. Clarke pitched well during his first major-league start May 7 with two runs allowed over six innings, but was still returned to the minors as a part of a roster shuffle. Arizona doesn't have another off day until June 6, so Clarke could be in store for a longer stay in the majors this time around.