According to the Boston Globe, Gronkowski has been running around at OTAs making the needed cuts, plants, etc. Coming off his type of injury one cannot help but be encouraged by this news
Vince Wikfork has been probably the biggest question mark due to his age. But according to multiple sources he's participated in half of the OTAs and plans to increase his work load throughout the summer. No one is quite sure one about their status for training camp but it does look possible that both could be ready to go for the season opener.
Jerod Mayo has also been a full participant in OTAs. The fact that these guys are up and running right now is very encouraging. I'll be keeping a close eye on this so ill definently keep everyone posted.