Take a team. Now put their top two interior pass rushers on IR. Put a starting CB on IR. Release the #3 CB due to ineffectiveness due to injury. Cut two of the top 3 safeties because they both regressed badly in the offseason. Knock out the top two ILBs for a few weeks. Make 4 other defenders questionable on the injury report. No matter what you start with, the result isn't going to look good.
My basic problem is even before the events you listed the Patriots defense was weak. Kinda an older weaker version of 2010. I like the Patriots and hope they win, even if they just beat the Jets that is a mini superbowl.
Even without the loses to the roster it was evident that the defense wasn't any good. All the missing players were basically average or below average, not a single difference maker. Now we are in year 4 of a rebuliding process and the defense has not improved. That is what disapoints some of us.
DL - Wright - coming off a concussion, pretty nice #5 defensive lineman, really hasn't done much or been consistent enough to matter
Pryor - again, an below average player that would be a good $5 or #6 defensive lineman on a good team
S - Sanders & Merriweather - pretty much average
LB - Fletcher and Spikes - most LBs miss some time, these guys are not exactly great, every team in the NFL relies on their subs
CB - Bodden - was a nice player, average NFL CB two years ago before surgery
Even with this cast of JAGS the defense wasn't going to be very good. Not hard to see this coming, the lack of quality additions for the past 2-3 years left them reaching for washed up players like Ellis & Haynesworth making rebuilding even harder. They screwed themselves big time this year and maybe for the next few years.