The forgotten ones, the players who early in the year were placed on IR that could contribute:
Dane Fletcher - depth ILB who was coming along amazingly well before he tore his ACL in the pre-season.
Fletcher was a Special teams stand out and started five games in 2011, doing well. That pre-season he had looked like an improved player who had a strong grasp of the D. At worst, he would have been valuable sub/back-up capable of stepping in and playing satisfactorily.
Ballard was an undrafted FA who had worked his way up to starter in the 2012 SB for the Giants, it is possible that Ballard returns from his injury and becomes the solid back-up to Gronk that the team has been without the past two seasons.
Ras Dowling - Was drafted to be an immediate starter, and instead has spent the majority of two seasons on IR.
If Dowling is going to have any career with the Patriots, he will have to make 2013 a stand out one starting with the pre-season, Dowling has the potential to be a solid starting CB... and he'll be given one more chance to prove himself before being shown the door.
Josh Barrett - Is coming back from microfracture knee surgery, after coming back from some other injury the year prior. He has played only five games in the past three seasons, having been waived by the Broncos in 2010 and claimed off waivers by the Patriots.
Barrett, like Dowling, will likely be given one more shot to prove himself before being shown the door. But unlike Dowling, the Patriots have little invested in him, and he could easily not be given another shot.
In essence, four players that contributed nothing last season, that could not just make the roster in 2013, but make an impact as well.