Peacock (10-1, 3.30 ERA) has been reborn this season, thriving as a starter and long reliever for the Astros (76-47).
He spent one season with the Oakland organization (he did not pitch for the Athletics in 2012) before joining Houston via trade Feb. 4, 2013. He has remade his delivery in part because of years of injury issues, and the results of his labor have paid dividends.
"It's been exceptional," Astros manager A.J. Hinch said. "Watching him evolve as a pitcher over the last couple of years has really come together this year with his ability to miss bats. He's had to change the way he pitches mostly out of health issues over the last couple of years.
"He's battled his control in the past. He's really found his niche in his delivery that synced up to where he can use the weapons that everyone loved from the beginning of him being a prospect to now him being arguably our most consistent pitcher this entire year outside of (Dallas) Keuchel.
"The strikeout numbers are real. It takes a lot to accumulate those kind of strikeout numbers with his strike-throwing ability which has improved, his wipeout breaking ball that he's come up with over the last six months, 12 months."
Peacock is 2-0 with a 2.19 ERA over four games (two starts) against the Athletics this season and 3-4 with a 4.25 ERA over 14 career appearances (11 starts) against Oakland.
Right-hander Jharel Cotton (5-10, 5.92 ERA) will start the series finale for Oakland (53-70).
He is 0-1 with a 3.48 ERA over two career starts against the Astros, with that loss coming in his only start against Houston this season: a 9-4 setback at Minute Maid Park on April 28 when he allowed six runs (three earned) on 10 hits and one walk with four strikeouts over 4 1/3 innings.
After shifting super utility man Chad Pinder from right field to center in the eighth inning Friday night, Athletics manager Bob Melvin revealed plans to do so again in the future. Pinder served as a middle infielder last season before assuming some corner outfield duties this year.
"We also want to take a look at (Boog) Powell and certainly Rajai (Davis) will play against the lefties," Melvin said. "We'll get (Pinder) out there, I'm not sure when. It might be more in-game type moves like (Friday), but at some point in time we'll get him a start. I'm just not sure when.
"Center field is a little different dynamic in that you're dealing with both corner guys. Usually the guy in center is more of a speed guy. But he's done a really nice job in the corners, so as of right now we feel like we have two guys that can hold down the fort in center field at least to start."