By mid-August, the Astros opened such a sizable lead in the American League West that even after losing three of four in Oakland, they escaped the Bay Area with a seven-game division lead.
In the four weeks since, Houston has inched further ahead in pursuit of its third consecutive division title. With their four-game series sweep of the visiting Seattle Mariners, completed Sunday with a 21-1 victory, the Astros reduced their magic number to clinch the AL West to 10 games.
With the Athletics paying a visit for a four-game set starting Monday, the Astros can essentially achieve that goal should they continue with their winning ways.
The Astros enter the series 16-4 over their last 20 games and 27-4 over their last 31 games at Minute Maid Park. Houston is 27-2 at home against divisional foes, and by maintaining that momentum against Oakland, the Astros can turn their attention to home-field advantage in the postseason.
"We put up a lot of wins, and I like the way we're playing," Astros manager AJ Hinch said. "We have a one-game mentality, which is good. We know it's a four-game series, we know what's at stake.
"I think the mentality that served us well is just to win today's game and get to the next one. We have (Zack) Greinke going tomorrow, that's the game to focus on. If we can build a closer and closer chance to win the division, that is our first goal. And the sooner that we can do that, the better."
Greinke (14-5, 3.09 ERA) will start the series opener for the Astros on Monday. He took his first loss in six starts with the Astros in his previous outing, allowing four runs on eight hits with four strikeouts over six innings in a 4-2 setback against the Milwaukee Brewers on Sept. 3.
Greinke has surrendered nine earned runs on 14 hits over 11 2/3 innings in his last two starts, with the Astros losing both of those contests.
He is 7-2 with a 2.97 ERA over 17 career appearances (13 starts) against the Athletics. Greinke limited Oakland to one run on four hits and three walks with six strikeouts over seven innings in a 4-1 win on Aug. 18, his third start after he joined the Astros.
Right-hander Mike Fiers (14-3, 3.51 ERA) gets the ball for Oakland to open the four-game series.
Fiers is 12-0 with a 2.59 ERA over his last 21 starts, a streak that began with his no-hitter against the Cincinnati Reds on May 7. He has allowed a .639 OPS during his winning streak, with the Athletics going 17-4 in those starts.
Fiers, who went 21-19 with a 4.59 ERA over parts of three seasons (2015-17) with the Astros, is 1-2 with a 5.63 ERA over seven career starts against Houston.
In four starts against the Astros this season, Fiers has not recorded a decision while posting a 6.14 ERA. Oakland has won Fiers' previous two starts against the Astros.
Oakland, 12-6 since dropping the finale of that series with Houston last month, kept pace with a 3-1 win over Detroit on Sunday and maintained its 1 1/2-game lead over the Cleveland Indians for the second AL wild card.
The Athletics saddled Houston with one of its two home losses against AL West opponents, rallying in the ninth inning on July 23 before winning 4-3 in 11.
First baseman Matt Olson went 5 for 12 in the A's three-game series with the Tigers, and also tied his season high with his 29th homer of the season.
Olson had a 10-game hitting streak snapped Sunday, but he talked about gaining consistency at the plate and losing streakiness.
"I just feel like I'm becoming more aware of my swing," Olson told MLB.com. "When something feels off, I feel like I'm addressing it sooner than I have in the past and getting back on track. That's been big for me this year."
--Field Level Media