IMO, it's a mortal lock that Chris Clemons and his $7.5M contract for 2014 are gone, as a cap cut (barring Clemons accepting a MASSIVE pay cut, which I wouldn't expect him to do).
That leaves Cliff Avril and Benson Mayowa at LEO for 2014. (I don't consider O'Brien Schofield a true LEO - because he isn't - and he'll be a FA this off-season as well, and likely looking for a place where the line to playing time is a little shorter, given that he was a healthy scratch on more than a couple of gamedays this season).
Mayowa needed exactly what he got in 2013 - a "redshirt" year to watch, learn, and get stronger. If the Hawks choose to make Avril the 'starter' at LEO next year, Mayowa should be well-primed to compete as the #2 LEO while working into the rotation on passing downs.
I also fully expect the Hawks to bring in another LEO candidate via the draft - perhaps even as early as the 1st round depending on how the board shakes down. Stanford's Trent Murphy and Auburn's Dee Ford are two names I'd keep in mind for our first pick. For the middle of the draft, Georgia Tech's Jeremiah Attouchou could also hear his name called by the Hawks as a good LEO fit.