This weekend's series between the clubs could go a long way in determining their postseason fate.The Athletics look to avenge a four-game sweep at the hands of Cleveland earlier this year as they host the Indians on Friday night.Oakland (68-52) is currently in the driver's seat for a wild-card berth, battling Tampa Bay for the top spot and 3 1/2 games ahead of Cleveland (65-56), though the Athletics have lost nine of 14 and the Indians are 3-7 in their last 10 with victories over the sub-.500 Los Angeles Angels and Minnesota.Cleveland, however, did win its second straight road series with a 9-8 victory over the Twins in 12 innings on Wednesday. Michael Brantley drove in the go-ahead run with a sacrifice fly after Chris Perez blew a save opportunity in the 10th inning."We just need to keep trying to win series," said Mike Aviles, who was 2 for 6 with two RBIs. "I think the biggest thing is going game-by-game and hopefully the series will start piling up."The Indians will likely need a much better showing from Justin Masterson (13-8, 3.59 ERA). The right-hander has surrendered nine earned runs over 11 1/3 innings in his last two starts after allowing four in his previous four outings.He lasted only 4 1/3 innings Sunday against the Angels and would have been on the hook for a second straight loss if not for Cleveland's late offensive outburst.It was the sinkerballer's shortest start since Aug. 30 against Oakland when he gave up eight runs and eight hits over four innings of a 12-7 home loss."It wasn't going the way we'd like it to," Masterson told the team's official website. "But the boys came back and you saw some offensive power, and I think that's a great thing to see by this team."The Athletics had regularly been a nuisance for Masterson until a 4-3 win over Oakland on May 8, allowing three runs and four hits over seven innings. It was his first win versus the Athletics since 2010 after losing his previous three starts against them, though he still owns a 7.42 ERA in 11 career appearances.The Athletics will call on A.J. Griffin (10-8, 3.88), who was on the losing end of that May 8 contest, yielding four runs over 6 2/3 innings. The three earned runs came on two homers, including one by Nick Swisher, who is 3 for 7 off Griffin with another home run.Griffin has yielded a major league-worst 28 home runs but kept Toronto inside the park while allowing three runs -- two earned -- over 5 2/3 innings before leaving without a decision in Oakland's 6-4 road win Sunday, though he did walk a career-high six. He had given up 10 homers in his previous four starts.Oakland had lost six of seven at home prior to a 5-0 win over Houston on Thursday as Sonnie Gray earned his first win and fellow rookie Nate Freiman drove in four runs on four hits.Alberto Callaspo was hitless Thursday but is 8 for 20 over his last eight games with five doubles. He's just 4 for 19 off Masterson.Oakland had won eight straight in the series prior to Cleveland's four-game sweep earlier this year.