For those who aren't familiar with stress fractures, they're basically small, hairline breaks in the bone of the foot. You may not realize you have one until the pain flares up, which is more than likely what happened to Corey Peters. And once you have one, the only real treatment is rest.
Players like Tom Brady have actually played through stress fractures. That's swell and all, but before you accuse Peters of being a wimp, remember that he's carrying around close to 100 pounds more than the average quarterback. You don't want to play around with a fracture in your foot when you feet take the kind of abuse that a defensive tackle is subjected to.
So what does this mean for Peters? The average recovery time is supposed to be anywhere from 12 to 16 weeks, and Peters has presumably been off his foot for quite some time now. The Falcons put him on the PUP list because they clearly expect him to come back before the end of the season, and hopefully he'll be completely healed by the end of six weeks. A setback would not be totally surprising, but I'm hoping we won't see one.
So there you have it. Peters has a stress fracture and should return to the team when he's eligible after week six, but we just don't know. Comforting, isn't it?