With Brandon Beachy and Ryan Dempster both battling injuries, Miley's 2.19 ERA stands atop the leaderboard.
For a rookie who entered the season as the D-backs' long relief pitcher, Miley's rise to prominence has been meteoric. The 25-year-old will look to put together one more standout performance Saturday in Milwaukee in the second game of the weekend set before the All-Star Game rosters are announced on Sunday on TBS.
"I try to keep that out of my head as much as possible," Miley said of his All-Star potential. "It'd be great, but we have to focus on winning ballgames."
In his last four outings, Miley has tossed at least seven innings and gave up just one run in each. He became only the second left-hander in franchise history to string together such a run, with the other being Randy Johnson.
In his last start, Miley lasted eight innings against the Cubs, allowing just a solo home run and striking out seven in a 5-1 victory.
"He doesn't back down from anybody, he just throws strike one every time," D-backs catcher Miguel Montero said. "He competes and believes in his stuff."
Opposing Miley for the Brewers will be fellow rookie Michael Fiers. In five starts this season, Fiers has gone at least five innings each time, and at least seven on three occasions.
"I think the way he pitches, when he goes out there now we have a good feeling that he's not just going to throw a nice game, but he's going to give us length," Brewers manager Ron Roenicke said. "When you know a guy can give you length, and you know he's going to keep you in ballgames, it's huge. It's huge how we plan how to go into that game and what we're going to do maybe the next series."
Brewers: Marcum staying on DL
Shaun Marcum threw 35 pitches on flat ground on Friday, but his stiff right elbow will sideline him through the All-Star break, according to Roenicke.
"I don't think he'll make a start before the All-Star break. I don't think there's any way we can do that," Roenicke said.
Roenicke said Marcum was, "a little better, but still felt it," referring to the tightness in his elbow that developed after a June 14 start in Kansas City. Marcum is eligible to come off the disabled list on Saturday, but won't.
Marcum had a 3.39 ERA before going down and held opponents to a .227 batting average, best among Brewers starters.
"Hopefully we get him to where he's confident that he can go out there and throw the ball and not feel anything," Roenicke said. "That's where we're trying to get him to."
D-backs: Bauer expected to make next start
Trevor Bauer was still dealing with tightness in his groin on Friday, but both the right-hander and manager Kirk Gibson said the injury should not prevent him from making his scheduled start Tuesday.
"He seems to be able to pitch with it," Gibson said. "We've tested it; he's strong as a bull. He's very, very strong. That's encouraging. I expect he'll be able to make his next start."
Bauer dealt with the issue in the third inning of his debut on Thursday in Atlanta, and he said it caused him to alter his mechanics and therefore impacted his command.
"A lot of hip repositioning stuff to try to take off some of the pressure and some soft tissue stuff to get some of the swelling out of there and get it to calm down a little bit," Bauer said of the treatment he received Friday. "It's been worse in [Double-A] Mobile and I never missed a start. I'll be fine."
With his second cycle in the past 11 days on Friday, D-backs second baseman Aaron Hill joined Babe Herman (1931) as the only two players in the live-ball era (since 1920) with two cycles in one season.
The Brewers' Corey Hart has appeared in 30 games at first base (25 starts) and has yet to commit an error.