Much has been made in recent weeks about Bills rookies getting a shot at playing time on defense. Marcell Dareus (first round) has been a starter on the defensive line all season, but he's recently been joined by inside linebacker Kelvin Sheppard (third round), cornerback Aaron Williams (second round) and strong safety Da'Norris Searcy (fourth round).
Tennessee has had two rookie starters all season, as linebacker Akeem Ayers (second round) has started every game, while defensive tackle Jurrell Casey (third round) has started all but one. Middle linebacker Colin McCarthy (fourth round) has impressed in spot duty, and will start Sunday as an injury fill-in for veteran Barrett Ruud.
Both defenses are similar in that they struggle to generate a pass rush and aren't flashy. The big difference, however, is very important: Jerry Gray's defense gives up 19.3 points per game - the seventh-lowest total in the league, while the Bills give up the fifth-highest per-game point total at 25.5.