"We have a plan, but we want to see him one more time down there tomorrow," Hale said.
Miller is 5-1 with a 3.52 ERA in seven starts for Reno after going 2-9 with a 7.14 ERA in 14 starts for the D-backs.
As of now, Arizona's rotation consists of Zack Greinke, Robbie Ray, Braden Shipley, Archie Bradley and Zack Godley. Miller will be back in the fold by September and perhaps so will Patrick Corbin, who was moved to the bullpen earlier this month after struggling.
Not only does Hale want to give Miller and Corbin another chance, but the team is monitoring the innings of its young starters, Ray and Bradley, who have not pitched this much in their professional careers.
"We've been talking for three weeks on innings and how many more innings from last year is enough, how much is too much," Hale said. "We're really just watching these guys and seeing how they've looked velocity-wise, if they're dropping."
Now, the D-backs will have to determine exactly how they'll use their starters in the final month of the season.
"We're going to have a lot of guys here," Hale said. "Do we split games? Do we skip somebody? We're still going to figure that out. We're going to start to get real serious about it here this weekend."
• Outfielder Yasmany Tomas (mid-back tightness) was out of the lineup on Wednesday after being removed early from Tuesday's game. He was available to come off the bench and the D-backs don't see it being an issue moving forward.
"He's feeling much better today," Hale said.
• Starter Rubby De La Rosa (right elbow inflammation) will throw his second side session of the week on either Thursday or Friday. He is then scheduled to throw a rehab game in the Arizona Rookie League on Sunday.
Jake Rill is a reporter for MLB.com based in Phoenix. This story was not subject to the approval of Major League Baseball or its clubs.