Not going to name names out of respect for the kids, but I could see at least three and maybe four guys not coming back for a fifth year (whether due to injury, lack of production, or placement on the depth chart) unless they have a significant breakthrough in 2017.
And, as we unfortunately learned last year, there's always the potential for a medical retirement or unanticipated transfer.
It's also not completely out of the question that XWash could take a redshirt this year and come back in 2018.
(There's a reason it's extremely difficult for outsiders to correctly calculate remaining scholarships... just so many variables.)