Davis' cancerous thyroid gland was removed April 10. He was declared cancer-free this month and rejoined the Diamondbacks for this week's series at Florida, and manager Bob Melvin has said he'll start Friday night against the Braves.
To make room for Davis, Arizona designated right-hander Brandon Medders for assignment. He was 1-0 with a 4.58 ERA in 18 games pitching out of the bullpen.
Davis, who has missed 36 games this season, made two rehab starts for Triple-A Tucson.
The cancer was discovered before the season, but he made two starts before undergoing surgery April 10. He is 1-1 with a 3.72 ERA.