The Diamondbacks optioned Bukauskas to Triple-A Reno following Wednesday's game against the Giants.
The righty has appeared in three games since being recalled July 30, most recently throwing a scoreless inning in Wednesday's contest. Bukauskas' overall numbers this season are not good, though, as he has a 7.79 ERA and 1.79 WHIP in 17.1 big-league relief innings.