The A's are lucky. With Nick Punto, Jed Lowrie, John Jaso and Sean Doolittle all somewhat close to returning from relatively short-term DL stints, roster decisions are getting much easier. Instead of 25 spots to distribute among 30 or so players, there are suddenly 40 in September.
The 25 players currently on Oakland's roster should be fine, obviously; they're all on the 40-man roster, and there's no competition for space that would cause any of them to be demoted.
The A's can, when all are healthy, carry four catchers, plus some extra weight in the middle infield and outfield. John Jaso's concussion prognosis is relatively unknown at this point, but he'll return if and when he's healthy. So Geovany Soto will stay, along with Derek Norris and Stephen Vogt, the latter of whom likely won't catch for the rest of the season thanks to a lingering foot injury.
Billy Burns will join the club as an extra outfielder. He likely won't play much, but if the A's ever find themselves in a scenario where they need a stolen base late in the game, they'll have someone who runs for a living waiting in the wings.
Nate Freiman will return to the A's on Tuesday, and Jed Lowrie could rejoin the team with him. Lowrie, as Susan Slusser reports in that article, expects to play in a rehab game for Triple-A Sacramento on Saturday, and if all goes well it's easy to imagine him back with the big club as soon as Monday or Tuesday.
Lowrie, Punto, Doolittle, and Jaso will be reactivated as soon as they're healthy and ready to contribute; again, thanks to the roster expansions on Monday, there won't be any need for reciprocal 25-man roster moves.
Other 40-man additions could include Shane Peterson, a Sacramento mainstay who has never been given a legit shot to stick in the big leagues despite putting up a slash line of .310/.382/.463 in 133 games with the River Cats this season.
Arnold Leon would have been a candidate at the beginning of the year, but faced serious struggles in the state capital this season, posting a 5.12 ERA in 139 innings with Sacramento. Josh Lindblom has been slightly worse in 83 innings — he owns a 5.86 ERA with the River Cats.
The one bit of help they could get in the bullpen, if you count Scribner as an injury replacement for Doolittle and not as a September call-up, might come from Joe Savery. The 28-year-old lefty threw four scoreless innings for Oakland prior to his May demotion, and has been solid with the River Cats, sporting a 2.98 ERA through 48⅓ innings.
So, to recap, Burns will likely be brought up as an extra outfielder, Peterson as a utility player, and Savery for bullpen depth. Evan Scribner will stay, and as Lowrie, Punto, Doolittle, and Jaso become healthy — potentially in that order — they'll be activated.
The September call-ups, as usual, won't make a huge splash, especially in the thick of a heated pennant race. But Burns will be useful late in games when the A's need a defensive boost or a stolen base, Peterson is extremely versatile, and Savery's presence in the bullpen really couldn't hurt. The roster moves that will have real impacts are the respective returns of Freiman (not frum injury), plus Lowrie, Jaso, Doolittle, and Punto, and they can't come soon enough for the struggling A's.