‘Beyond those top four, however, the Bills have some questions. Isaiah McKenzie and Andre Roberts are scheduled for free agency. McKenzie ran about a million miles, keeping defenses honest by going in motion so frequently. He finished with 30 catches for 282 yards and five touchdowns. That’s solid production for a No. 4 receiver. If McKenzie leaves, the Bills will be on the hunt for a jack-of-all-trades receiver to fill his role.’