A-Rod was hurt game 1 and Cousins was hurt game 8. I don't see how the extra game had anything to do with that. Lots of QBs got injured this year overall and they are already treated with kid gloves. Injuries (unfortunately) are part of the game in all sports at every level.
I'd understand getting rid of the weekly Thursday games, and keep those as only a season opener and Thanksgiving thing (teams playing them get their bye week headed into that game). Those are the games (along with the London games) that players complain about effecting their health (rest/recovery). Add to that there are already very tight rules on practices in both time and contact allowed.