Game by game, the A's are marking off checkpoints as they march toward the postseason.
Having claimed their second straight American League West title five days earlier, the A's secured home-field advantage for the AL Division Series with their series-opening win over the Mariners on Friday in their final series of the regular season.
Now, their focus is on the best record in the AL and securing home-field advantage for the entirety of their time in the playoffs. Oakland trails Boston by two games, meaning the Red Sox will have to lose their final two games against the Orioles and the A's will have to win their final two against Seattle.
Jarrod Parker will take the mound for the A's on Saturday afternoon. Parker is 10-2 with a 2.90 ERA and .214 opponents' batting average over his past 23 starts since May 17, with the batting average ranking third lowest in the AL over that span and the ERA ranking eighth.
"We know it's right there," Parker said after his last start -- the day prior to the A's winning the division. "If we handle what we do and we win games, it's going to happen."
While the goal has shifted, the same mentality applies.
Rookie right-hander Brandon Mauer will toe the rubber for the Mariners in Eric Wedge's penultimate game as Seattle's manager. Wedge informed the team that he will not come back in 2014, though general manager Jack Zduriencik said the organization was looking forward to having him back.
Maurer made his longest start of the year against Kansas City on Monday, going seven innings while allowing just one run on four hits in a no-decision.
Still, Maurer has struggled this year, giving up big middle innings -- a habit Wedge says he has to break out of if he wants to make it as a starter.
"He has to understand the difference between the beginning and the middle of the game, and the beginning and the end of the game," Wedge said. "There's a reason why things were happening the way they were happening, but he can control that. He has that type of stuff, he has that type of ability and I think he's learning that more and more with each outing."
Mariners: Wedge informs club he won't return in '14
Saying it was "painfully obvious" that he wasn't going to be able to move forward with the team, Wedge informed the club Friday he will not be returning next season.
Wedge declined a one-year contract extension last offseason and said no subsequent offer had been put on the table, but Zduriencik said the club wanted Wedge to return and was prepared to inform him of that during a scheduled postseason meeting Monday.
Instead, Wedge called Zduriencik on Thursday to request a meeting on the off-day, then informed the GM he wouldn't be returning on Friday morning.
"Eric's job was not in danger," Zduriencik said. "This was his decision. I was looking forward to having Eric back."
Wedge, 45, will finish out the final two games of his three-year contract this weekend. He has a 212-272 record in Seattle and a career mark of 773-845 after spending seven years with the Indians from 2003-09.
"It's tough, it's disappointing, it's frustrating, it's upsetting," Wedge said prior to Friday's game. "Sometimes people just don't see things the same way and things just don't work out. It wasn't for a lack of trying, I wanted it to work, but it's just not going to."
Cespedes exits early in return to left field
As expected, Yoenis Cespedes returned to the outfield on Friday for the first time in two weeks. Unexpected was his early exit from the game because of recurring right shoulder soreness.
While nursing the shoulder, Cespedes made nine consecutive starts at designated hitter, before finding his way back to left field for the club's three-game series opener in Seattle. He lasted just 3 1/2 innings and was replaced by Seth Smith to start the top of the fourth.
Just hours earlier, manager Bob Melvin had relayed how happy he was to get Cespedes back on defense -- and for more than one reason.
"It's nice to get him back out there. He's a pain in the [rear] on the bench," said Melvin, smiling. "He's a guy that really wants to play the outfield. He knows he was relegated to DH duties for a reason, but his true game comes when he's playing the outfield, so he's pretty excited about being back out there today."
Cespedes is batting .226 in 27 games as DH, compared to .254 through 92 games as a left fielder this season.
• The Mariners 185 home runs rank second in the Major Leagues and are the seventh-most in franchise history.
• Cespedes is batting .314 (27-for-86) with 12 runs, six home runs and 19 RBIs in 22 games in September. He leads the AL in RBIs this month and is tied for third in home runs.
• Seattle is nearly a .500 club when rookie catcher Mike Zunino plays, as compared to playing just .418 ball when he doesn't.
• A's starting pitchers have allowed two earned runs or fewer in 14 of 16 games since Sept. 7 and are 11-1 with a 2.68 ERA.
Jeff Kirshman is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.