I don't want to put cold water on this Sharper thing but Jenkins has done a fairly decent job in Sharper's absence. Do we cast Jenkins to the side? MJ is not in Sharper's league yet but he's younger and certainly more athletic.
Heck, no we don't cast Jenkins aside. He's got youth on his side and, as you said, athleticism. Between the two of them we may have the best Safety ever to play the game! :) But I do believe Sharper knows his playing days are waning. And if he is unselfish enough to pass some of the wisdom along, well, wow! Plus, we may need him very soon if Sharper's knee doesn't hold up.