Brent Grimes didn't play at all last year, except for a little bit in the first game.
The Falcons have basically been without their #1 and #2 offensive players in Julio and Roddy, and their #1 and #2 defensive players in Weatherspoon and Biermann for most of the year. Add to that the lack of clutch in the first few games (4 one-possession losses in the first 5 games, though the New England game probably shouldn't have counted) and they went from good to terrible pretty quickly. When an offense that's only good at QB, WR and TE loses both top receivers, and a defense that was never good loses their best pass rushers, bad things usually happen. They have enough to upset some of the good teams on the second half of their schedule, but the Falcons' season was lost once the injuries started piling up.
The Packers might be in a similar situation if Seneca Wallace is as bad as he was Monday night. They had an injury list longer than the Falcons, but at least they had Aaron fuckin Rodgers to keep the offense on track. If they lose three games in their next four behind Wallace, though, they might not even make it to January.