Ron Roenicke has said the team will likely only call up players that they could actually use in September, meaning we're probably more likely to see role players than big name prospects. And really, there's nothing wrong with that for a contending team with eyes on the postseason.
So with that in mind, there are a few guys that would make sense.
Expanded rosters means the team can afford to bring in a couple extra arms, which could be big when it comes to making sure John Axford and Francisco Rodriguez are fresh for a potential playoff run. DiFelice has had success in the big leagues before, so it wouldn't be surprising to see Roenicke trust him to fill the middle innings of a close game. His cutter makes him an effective ROOGY, which could make him an effective situational weapon in the last few weeks of the season.
With the rosters expanded, Dillard can return as the team's longman, even if we forget he's on the roster every now and then. At least he could keep the bullpen entertained with his Harry Caray impression and can soak up an inning or two in a blowout.
With Rickie Weeks returning soon and Jerry Hairston, Josh Wilson, and Craig Counsell all on the roster, odds are Farris wouldn't see the field very often if he were called up in September. Where he could be used, though, is as a late-inning pinch-runner -- something the team hasn't really had since Carlos Gomez went down with his broken collarbone. Gomez will return on Thursday, but Farris would add more speed and youth to a bench that's mostly old and slow.
If Taylor Green sticks around, it'll be hard to find Gamel much time (if any) in the field, but he would be another pinch-hitting option for Roenicke. Gut feeling says Roenicke would likely use Gamel earlier in the game, saving the likes of Mark Kotsay for a late-inning pinch-hitting spot. Gamel has struggled to find success without regular at-bats at the big league level, but maybe a strong September could convince the club he's a viable option in a world without Prince Fielder next year.
With the expanded rosters, it would make sense for the Brewers to treat themselves to the luxury of a third catcher. They've gone with three catchers a couple of times this season (with Wil Nieves and Mike Rivera) to get George Kottaras some ABs as a pinch-hitter, and Maldonado would be able to do the same thing for the team in September. Maldonado is also an outstanding defender -- likely the best defensive catcher in the entire organization -- so he could be used as a late-inning defensive replacement if need be (although it seems unlikely the team would trust a rookie catcher in that scenario). Maldonado hits right-handed, but probably wouldn't be counted on to hit much.