Here is former Packer cap guy, Andrew Brandt talking about the brutal cutting season in the NFL...
http://mmqb.si.com/2013/08/08/nfl-preseason-cuts/
"There are usually between four and six spots that are open to competition, depending largely on numbers and personnel groupings rather than the performance of players on the bubble."
"For instance, if we had a couple of young offensive linemen we wanted to keep on the roster for any number of reasons—it could even be the limited practice availability of older linemen—we would “go heavy” up front. This would mean the end of the road for a sixth linebacker, a fifth safety or a fourth running back. Every team makes these roster decisions that affect players at other positions regardless of their performance."