Triggs, 27, made his Major League debut on April 25 and compiled a 8.00 ERA in 10 relief appearances before returning to Triple-A, where he has a 3.48 ERA.
Triggs totaled 76 pitches in four relief innings in Houston in his last appearance for Oakland on June 3, and Melvin noted, "I don't expect him to do that [Saturday], but we'll see how it goes."
"We're really not too worried about how much we get from him," Melvin said. "We're going to have an extra pitcher here regardless, a deep bullpen, so we'll mix and match a little bit."
Among the A's available arms for Saturday: right-hander Zach Neal, who also has the ability to give the A's multiple innings. Neal was considered a candidate to start.
Jane Lee has covered the A's for MLB.com since 2010. This story was not subject to the approval of Major League Baseball or its clubs.