Deone Walker returns an interceptions against the Denver Broncos. The Buffalo Bills are expected to see some big changes on defense after Sean McDermott was fired and Jim Leonhard brought on as new defensive coordinator, and that could include a shift in position for a breakout rookie. Leonhard has promised to bring an aggressive new style of defense, along with a 3-4 base defense that will call for a position that didn’t really exist under McDermott’s 4-3 — a true nose tackle. One insider