PHOENIX -- On Friday, one day after D-backs manager Chip Hale acknowledged Shelby Miller was dealing with a lingering finger issue, the D-backs placed the struggling right-hander on the 15-day disabled list, retroactive to Wednesday, with a sprained right index finger.
Miller is 1-6 with a 7.09 ERA in 10 starts this year. He banged his hand on the Petco Park mound twice during his follow-through on April 16, causing his index finger to throb and forcing him to leave the game in the second inning.
"Obviously he hasn't been successful, as successful as we feel like he can be, and it's just his feel for the ball has not been as good as you want it," Hale said. "Definitely what we're going to be working with him on is getting him back to where he's our No. 2 guy. That's what we got him for, and we still believe he's going to be that when this injury is healed."
The D-backs acquired Miller in the offseason from Atlanta for a package that included last year's No. 1 overall Draft pick, Dansby Swanson. Miller's only quality start in 10 outings came against the Braves on May 7.
Right-hander Archie Bradley will take Miller's turn in the rotation in Sunday's series finale against the Padres. Bradley was scratched from his Thursday start for Triple-A Reno. He is 1-0 with a 7.84 ERA in two starts for the D-backs this season.

Rubby De La Rosa will join Miller on the DL after he underwent an MRI on his right elbow on Friday morning. Hale said De La Rosa had been experiencing soreness in his triceps and it became more localized in the elbow after his last start against the Pirates on Wednesday.
"Any time you shut a pitcher down, you've got to start it back up at some point," Hale said. "Obviously it's not going to be the 15 days, it'll be longer than that."
De La Rosa, who is 4-5 with a 4.15 ERA, said he expects to miss closer to a month.
The D-backs will recall left-hander Edwin Escobar from Reno to make his first career start in the Majors on Monday against the Astros. Escobar, who was claimed off waivers from the Red Sox on April 29, made two relief appearances for Boston in 2014.
Escobar is 2-1 with a 4.68 ERA in five Triple-A starts since coming to the D-backs organization.