No sources, but I can see TV Williams, Jared Tucker, and a few others who do not get any playing time may leave and go somewhere closer to home that allows them to get on the field.
Contributing player wise, I can see someone like Bone leave. People say he has been underutilized, but his biggest issue is he is slow and cannot get much separation against SEC competition. Now, if KY can somehow use him for jump balls and more end zone fade type of plays then he has a place on the team, but I am not sure he is willing to sit on the bench and only contribute for certain packages only.
RB wise, do not see anyone leaving. Boom and Jo Jo are injury prone. Two freshman coming in. Horton needs to be used the way he was recruited to be used (short yardage and goal line situations). Problem is he is not as physical as once thought, fumble prone, and runs too high. King will see a lot of time as a returner.