Honestly, Cooper and Fowler are the only players for whom we don't really have a replacement for.
*Losing Arie K. at LG is going to hurt. (never thought I'd say this going into the season)
*Losing Leon Brown at RG is addition by subtraction.
*Losing Austin Shepherd at RT is... well, Shepherd was experienced I suppose?
*Losing Jalston Fowler at FB will be difficult to replace. Other than Cooper, probably our biggest loss, in my opinion.
*Losing Cooper at WR: ouch.
*Losing Sims at QB... I'm not sure how this will affect us, to be honest. Sims was very effective for us and boy that guy can spin a pretty deep ball, but I'm not sure how irreplaceable he really is. He didn't come in with a lot of experience and still performed well, so I'm sure whoever we have step in will perform satisfactorily.
*Losing Christion Jones at WR/KR will also be addition by subtraction after how he played this year. He was a good blocker, I guess?
*Losing DeAndrew White at WR will hurt. He was a solid #2 option, but I think Ardarius Stewart is as good if not better than White. Plenty of depth.
*Losing Vogler at TE will be a nullity. Okay blocker.
*Losing Yeldon will hurt, but it's not as if we really had him for the second half of the season anyway. Plenty of depth here, too. He hurt his leg at some point either prior to the LSU game or in the LSU game when he fumbled the ball on our 4 yard line, and he hasn't been the same since.