Clarke (1-3) took the loss after allowing six runs on seven hits and two walks while striking out three over three innings against the Giants on Friday.
Clarke got lit up early, giving up a two-run homer in the second inning followed by a grand slam in the third. After beginning his stint as a major-league starter with two quality starts, the 26-year-old right-hander has failed to throw more than five innings in five subsequent starts. During that run, he's given up 21 runs (20 earned) on 28 hits and eight walks over 18 innings. The Diamondbacks are thin at starting pitcher, so expect Clarke to make his next turn Wednesday at home against the Dodgers.