Best/worst case scenario for Packer safeties

For the second year in a row, we present our best and worst case scenarios for every player on the Green Bay Packers 80-man pre-season roster. We start with the safeties:Nick Collins -- Collins has always been a solid but far from spectacular player. He's been a willing tackler but not a fierce hitter. He's been good in pass coverage but fails to make many interceptions. The best case scenario has him putting it all together in his fourth year and really, really breaking out. He has the talent. The worst case scenario has him losing his job to Aaron Rouse. If that happens, he's likely to stick around at least this year as a back-up, but he's unlikely to stick around Green Bay any longer in that type of role.Atari Bigby -- Bigby has the potential to build off a solid first year as a starting player. There's the possibility he will pick up where he became the NFL's defensive player of the month in December and a huge, huge playoff game against the Seattle Seaha...