Jon Duplantier was optioned back to Triple-A Reno following a three-inning relief appearance against the Atlanta Braves on Sunday.
Duplantier came in for the third inning in relief of starting pitcher Zack Godley and gave up three runs in the third.
After the rough third, he settled down and put out six of the next seven batters, allowing just an infield single to Dansby Swanson in the fifth.
The rookie pitcher earned his first major league win on Thursday against the Braves, striking out two batters in one inning of a 10-inning ball game to start the series.
He has made four appearances for Arizona this season with a 12:5 strikeout-to-walk ratio in eight innings pitched.
The D-backs did not announce a corresponding roster move and are expected to make a call-up before the start of the Pirates series on Monday.