Armed with sole possession of first place in the American League West for the first time since Aug. 6 after leapfrogging the Rangers on Friday, the A's will be out to maintain or extend their half-game advantage Saturday when the club hosts the bottom-dwelling Astros for the third meeting in a four-game set.
For the A's to take another step toward a repeat division crown, they'll have to deal with young left-hander Brett Oberholtzer, who has been nothing short of dominant since joining the Astros' rotation July 31.
The 24-year-old rookie is 4-1 with 26 strikeouts over six starts, with his 1.98 ERA leading the AL during that span. In his start on Sunday, Oberholtzer tossed the Astros' first complete-game shutout of the season in a 2-0 win against Seattle. The southpaw surrendered just four hits, all singles, across his nine innings.
"Everything was working," Astros catcher Jason Castro said. "I think the biggest thing, stuff aside, was that he was able to get ahead consistently all game. All breaking stuff was working that day, but getting ahead allowed him to use it more."
Hoping to derail Oberholtzer's momentum for Oakland will be another rookie in Dan Straily. After allowing six runs in 3 1/3 innings against the Orioles on Aug. 23, the right-hander has been much improved his last two starts, both wins. Straily gave up one run on eight hits over six innings against the Tigers on Aug. 28 then followed up that effort by defeating division-rival Texas on Monday. The 24-year-old lasted five innings, allowing two runs on just three hits in Oakland's 4-2 win.
"We knew coming into this month that we had six games against the Rangers," Straily said after the game. "We got to take care of business here and take care of business the rest of the month, too."
Astros: Grossman not rushing back from oblique recovery
Robbie Grossman has yet to pick up a bat and remains day to day as he recovers from a strained oblique incurred while swinging in the 12th inning of Tuesday's contest against the Twins.
Friday was his third game out of the lineup since the injury, and manager Bo Porter said it's still unclear when Grossman will be able to return.
"He's still a little sore," Porter said. "Again, those obliques can be funny. I think we just have to monitor it each and every day and see how he progresses."
Porter wasn't ready to determine whether Grossman will return before the season's end.
"I don't think we can sit here today and make that prediction," Porter said. "I think as time goes on, he's going to get treatment, and once he's physically able to play, we'll get him back in there.
A's: Jaso battling concussion symptoms
Recovering from a concussion sustained a month and a half ago, catcher John Jaso is still hoping he will play again this season, but with September already in full swing, time is running out.
"I'm wondering that," Jaso said Friday. "We'll just have to see how it goes. I can't control anything. All I can do is lie about it or tell the truth, and I'm just telling the truth and letting the professionals decide."
Jaso was batting .271 with a team-leading .387 on-base percentage following his last game in Houston on July 24.
"I've had concussions before and it hasn't taken this long," he said. "I'm not the first guy this has happened to, though, and I understand that. Still, it's such a helpless feeling and you don't really want it. You just come to a point you realize it is what it is."
• The A's are 13-4 this season against the Astros.
• Saturday's game is the 16th in a stretch of 20 games in 20 days for the Astros. The club is 6-9 thus far.
Tyler Emerick is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.