While the Bengals have one of the youngest defenses in the NFL, the AFC North has two of the oldest defenses in the league.
For years, the Pittsburgh Steelers and Baltimore Ravens have had defenses that have ranked among the league's best. In 2011, both teams ranked in the top third of the league in oldest defenses, per Mike Sando of ESPN.com.
With defensive end Aaron Smith and linebacker James Farrior not returning in Pittsburgh, the defense got younger. But by doing so, they got rid of players who provided leadership.
Injuries and suspensions also hurt Pittsburgh's defense, so age is not the only thing against them. James Harrison is an aggressive player, and he risks suspensions with his style of play. When Troy Polamalu suffers an injury, this defense struggles. After two seasons of battling injuries, he managed to stay healthy last season.
In Baltimore, the Ravens have to deal with aging veterans and nagging injuries. On a defense with arguably two of the greatest players at their positions, they are seeing their window of opportunity closing.
When the team was eliminated by New England in the AFC Championship, questions arose about the future of their stars on defense.
According to Gregg Rosenthal of NFL.com, it is still unknown if Ed Reed will play this season, but injuries have plagued him as of late. Whether or not the 33-year-old safety plays, the Ravens' window appears to be closing as well.
Linebacker Ray Lewis dealt with injuries last season, and his time in the league may be coming to an end. He is one of the best linebackers the game has seen, but age is starting to become a factor.
Perhaps the biggest reason for concern is the loss of Terrell Suggs. The 2011 Defensive Player of the Year tore his Achilles tendon in the offseason and will likely miss most of the season, according to USA Today.
Am I doubting these defenses? No.
Both teams draft very well on defense, especially Baltimore. Rookie Courtney Upshaw will try to replace Suggs, but they should not put pressure on him to do too much.
Cleveland has a nice young defense, but they have too many issues on offense to put them in a conversation with the rest of the division. With three AFC North teams making the playoffs last season, the Browns have a lot of work to do to catch up to their division rivals.
Age is starting to become an issue for both teams, and Cincinnati's young defense could become the best in the division in the near future.