Sabretooth's two appearences in the X-Men films so far have been wildly different both visually and in terms of personality. In the first film, the character had absolutely no connection with Wolverine whatsoever, instead being a quiet, aggressive henchman for Magneto. X-Men Origins: Wolverine fleshed the character out a little more to be more similar to his comic book roots, having an established past with Logan, but looking like a bit of a tool. Liev Shreiber did a great job of brining the mutant to life, but he just didn't look very animal like or even particularly threatening. X-Men: Apocalypse's revised timeline is going to enable Bryan Singer to change much of the established timeline that was set with the previous films, and Sabretooth is a prime candidate for this. Although the character, like Wolverine, has extremely fast healing capabilities (and therefore ages extremely slowly), you can't see Shreiber returning to the role for a second time. That only leaves Tyler Mane as a potential returning cast member, but considering the actor's almost non-existent filmography since the first film, we suspect that if Sabretooth does return, he'll be played by an entirely new actor.