'If the Bills lose Gillislee, they will end up with a need at running back. Second-year pro Jonathan Williams didn't do much as a rookie, and the team's depth chart looks a bit thin behind LeSean McCoy. Gillislee may seem like a huge loss after he burst onto the scene with 577 rushing yards and eight touchdowns in 2016. But the Bills could replace him. After all, they claimed Gillislee off waivers, and he was originally a fifth-round pick himself.'