The pair played together for Arizona in 2013 and 2014 and lived together on multiple occasions. They come small Louisiana towns north of New Orleans, about an hour apart. Miley grew up in Loranger and played college baseball at Southeastern Louisiana; Harris is from Slidell and went to LSU.
"It's close to home, and they've done a great job of putting together a championship team, year in and year out so I'm looking forward to seeing what happens," Miley said Friday after the Astros announced his $4.5 million, one-year contract.
Miley could earn an additional $500,000 in performance bonuses: $100,000 each for 10, 15, 20, 25 and 30 starts, and $100,000 apiece for 25, 35, 45, 55 and 60 relief appearances.
"This is a player that we're very excited about," Astros general manager Jeff Luhnow said. "We've been behind the scenes, pursuing him for a few years, and everything came together this year. We had an opportunity to bring him in, and he'll be part of a formidable starting rotation."
Miley was 5-2 with a 2.57 ERA in 16 starts and 80 2/3 innings for the Milwaukee Brewers last year and had a 1.23 ERA in four postseason starts, although one was a one-batter outing in a lefty/righty switch employed by Brewers manager Craig Counsell.
Astros manager A.J. Hinch was Arizona's director of player development when the Diamondbacks selected Miley with the 43rd overall pick in the 2008 amateur draft.
"That's an evolving pitcher from a young kid trying to find his way to now a veteran who understands the art of pitching a little bit better," Hinch said. "But the competitor has been the same, the approach has been there from the very beginning, and we're looking forward to having him."
Miley said the opportunity to play deep in the postseason also made the Astros attractive.
"That's what we play for," Miley said. "I got a little taste of it last year. Obviously, this is a championship-caliber ballclub, a great group of guys, and hopefully, we can get back there like they did in 2017."
Luhnow said Miley's style will fit well with the Astros, who play in hitter-friendly Minute Maid Park with its short home-run porch in left field.
"He gets ground balls, doesn't give up home runs, is able to get guys out," Luhnow said. "If he does that with our lineup and our bullpen, he's going to have a lot of success here."
Miley allowed only three home runs in 80 2/3 innings last year. He had a .237 opponents' batting average, including .225 against left-handed hitters.