He goes on the active/NFI list, which basically is just a formal way of saying he's not in practice. He comes off when he's cleared to practice.
In the meantime, with the roster spots cleared up by Peters going to the NFI and cutting Tatupu, the Falcons signed WR Tim Toone and DT Elisha Joseph. Toone was Mr. Irrelevant in 2010, drafted by the Lions out of Weber State. He is 27 and can return punts. He spent time last year on both Buffalo and Denver's p-squad after the Lions cut him.
Joseph was a UDFA last year with the Steelers, spending time on and off their practice squad. He's a run stuffer that is a NT out of Temple.
If the Falcons go the veteran DT route (and I doubt they will because we already have 4 bodies at DT), wouldn't be surprised to see Ronald Fields get a call. Fields was a 5th round pick by the 49ers in 2005, followed Nolan to Denver in '09, and then was with the Dolphins last summer before being cut.
"Vincere scis, Hannibal, victoria uti nescis" -- Maharbal, 216 B.C.E.