The Oakland Athletics are about to embark on a long stretch that could determine whether they're returning to the postseason for the first time in six years.
Before that, the A's will try to avoid overlooking the last-place Seattle Mariners and sweep this three-game set at Safeco Field on Sunday.
Oakland (78-60) is atop the AL wild-card standings and has a one-half game advantage over East co-leaders Baltimore and New York. The club that falls into second place in that division following their game Sunday will occupy the second wild-card position.
The A's position in the playoff race is very tenuous, as Los Angeles and Tampa Bay lurk 2 1/2 games back and Detroit trails by five.
Oakland's front-running status is about to undergo a major test. It opens a four-game road series against the Angels on Monday after being swept by them in three home games prior to visiting Seattle (67-73).
The next 13 contests come against the Orioles, Tigers, Yankees and AL West-leading Texas.
Until then, the A's would like finish off the Mariners this weekend after winning the first two games by 6-1 scores.
George Kottaras has provided some unexpected punch at the plate with two homers and five RBIs in the two wins. The catcher is 6 for 19 with four homers and 13 RBIs in his last five games, raising his average with Oakland 68 points to .222 in 13 games since being acquired in a trade from Milwaukee.
"He's been pretty amazing," manager Bob Melvin said. "You look at his average then you look at his home run numbers and RBIs. It seems like every home run he has hit for us has been a big home run. And (Saturday's) home run really had the same affect as (Friday's) home run."
Melvin is scheduled to turn to Tommy Milone (11-10, 3.94), who was battered in his most recent outing in Monday's 8-3 defeat to Los Angeles. The left-hander surrendered five runs and a season high-tying 10 hits - two homers - while getting pulled after three innings.
Milone had won his previous two starts while yielding one run and nine hits in 14 innings.
"From the first inning on I didn't feel comfortable and was struggling to keep the ball low," Milone said. "I forced myself to throw strikes and when I do that I leave it up in the zone."
Milone is 1-1 with a 2.25 ERA in three starts against the Mariners, putting together an impressive performance in his last visit to Seattle on June 25. He scattered seven hits in seven innings of the 1-0 victory.
The Mariners are expected to send Jason Vargas (14-9, 3.85) to the mound, and he's 3-0 with a 1.87 ERA in six home starts, a stretch that started with a 3-2 win over Oakland on June 26.
The left-hander allowed three runs and three hits while matching his career high with 10 strikeouts in 6 2-3 innings. He previously fanned 10 while yielding one strikeout in eight innings of a home victory over the A's on Sept. 26, 2011.
That performance was the first of a five-start stretch against Oakland during which he's 3-0 with a 1.78 ERA.
Vargas was impressive again at Safeco Field on Monday, allowing one run and six hits in seven innings of a 4-1 victory over Boston.