OAKLAND -- The A's will christen September play on Friday, marking the final month of a season that's mutated into a focus on the future.
A second consecutive disappointing season has the club positioned to evaluate a large handful of young players this month, many of whom are already in Oakland.
More are on the way, now that rosters have expanded, with the A's expected to call up several more prospects from Triple-A Nashville, while also being respectful of the Sounds' postseason run.
Oakland general manager David Forst acknowledged this week that "those games are important for them and for the development process," meaning they won't rush all of them up at once.
On Friday, only one or two players could be summoned ahead of a three-game series against the Red Sox, with Matt McBride being a likely bet to give the A's three catchers on their roster.
Within the next week, an influx of pitching could follow, notably right-handed prospects Jharel Cotton and Raúl Alcántara. Right-hander Daniel Mengden, who pitched to a 5.73 ERA in nine starts for the A's earlier this year, is also expected to return, potentially as soon as Saturday in place of injured lefty Sean Manaea.

Cotton, one of three pitchers acquired in the deal that sent Rich Hill and Josh Reddick to the Dodgers last month, has posted a 3.31 ERA in five starts for Nashville.
A native of the Virgin Islands, Cotton was a 20th-round Draft pick of the Dodgers in 2012. The 24-year-old, who is Oakland's No. 15 prospect, according to MLBPipeline.com, features a mid-90s fastball and a plus changeup. He would also bring a refreshing helping of optimism for fans as an otherwise uninspiring season comes to a close.
Alcantara, coincidentally, was also part of a Reddick trade. Alcantara and Reddick were two of three players that landed in Oakland in a 2011 deal that sent reliever Andrew Bailey and outfielder Ryan Sweeney to Boston.
Alcantara, 23, began the season in Double-A Midland before being promoted to Nashville, where he has dominated over seven outings, allowing just six earned runs in 45 2/3 innings.
Elsewhere, the A's could call on these position players at some point: first baseman Matt Olson and outfielder Jaycob Brugman.