Tavon Young's torn anterior cruciate ligament is significant blow to the Baltimore Ravens' upgraded secondary.

It also extends the Ravens' painful streak at cornerback.

Baltimore has placed 11 cornerbacks on injured reserve over the last three seasons. That includes including five last year, which tied the New Orleans Saints for most in the secondary, according to ESPN Stats & Information.

Over the years, when a Ravens defender was down on the ground, you'd assume it was a cornerback who was hurt. That's how frequent Baltimore players got injured at that position.

The endlessly swinging revolving door at one of the game's most important positions is the biggest reason why Baltimore signed veteran Brandon Carr and used the No. 16 overall pick on Marlon Humphrey this offseason. The Ravens were tired of going against Tom Brady in the playoffs with an inexperienced Rashaan Melvin. Baltimore wanted to avoid relying on struggling Shareece Wright to stop Ben Roethlisberger with the AFC North title on the line.

While the Ravens are set at outside cornerback with Humphrey, Carr and Jimmy Smith, the challenge is find someone to replace Young at the specialized position of nickelback. Covering the slot means being able to tackle, take on offensive linemen, read routes, move laterally, cover quick receivers, cover elite receivers, cover in short areas, cover deep, and rush the passer.

Young, who split time on the outside last season because injuries and ineffectiveness hit Baltimore's secondary, was expected to play primarily in the slot this season. It's his natural position. It's the spot the Ravens envisioned for him when they drafted him in the fourth round a year ago.

Now, there's a void in the middle of what could be the top secondary in the NFL. Can Lardarius Webb fill that role after showing signs of wear and tear at the age of 31? Could Maurice Canady step in after never playing one defensive snap in an NFL regular season? Does injured Kyle Arrington re-emerge after being sidelined all of last season with a concussion? Or perhaps Anthony Levine adds this to his endless list of jobs (cornerback, safety and linebacker)?

Young really saved the Ravens' secondary last season when he became a rookie starter on one of the top defenses in the league. He was the only cornerback on the team to play all 16 games and recorded the second-most snaps on Baltimore's defense. He came through after Wright struggled and Smith went down with another injury. The Ravens managed to be the NFL's No. 9 pass defense in large part because of Young's toughness and ability to attack the ball.

Baltimore is more prepared to lose a cornerback than any of the 10 years under coach John Harbaugh. Still, no one will deny watching Young getting helped off the field at Thursday's practice dealt a big hit to an an improved secondary.