PHOENIX -- With Zack Greinke set to be activated to start Tuesday night against the Mets, the D-backs cleared a roster spot for him by optioning reliever Evan Marshall to Triple-A Reno following Sunday afternoon's game.
Greinke has been on the disabled list with a left oblique strain since June 29.
The reigning National League Cy Young Award winner will be taking the place of right-hander Zack Godley in the rotation. Godley will shift to the bullpen, a role that he has occupied at times last year and five times this season.
That turned out to be a key factor when the D-backs discussed which starter to take out of the rotation.
"It was a very, very tough decision," D-backs manager Chip Hale said. "Godley, right now, is more suited of all those guys because he's done it, he's pitched out of the bullpen."
The move might not be permanent as Hale said the team will re-examine the situation in another seven to 10 days.