Fans are excited by the young talent in the Colorado secondary after watching the unit repeatedly blistered by Pac-12 Conference quarterbacks last season.

But senior free safety Ray Polk might be the key to improving the pass defense in 2012.

Polk generally deferred to older teammates in the past such as Anthony Perkins, Jimmy Smith and Jalil Brown, but now he will be the veteran face in the defensive huddle. Freshmen such as Kenneth Crawley, Yuri Wright, John Walker, Jeffrey Hall and Marques Mosley will look to him for on-field guidance.

There probably isn't a better role model for those young defenders and other young players on the team. Polk never has been one to put himself in bad situations off the field and no other defensive back knows the defense and what coordinator Greg Brown wants out of it more than him.

Polk also has proven he's willing to leave it all on the field for his teammates. He only recently fully recovered after playing most of last season with a damaged wrist and fractured sternum.

"It wasn't fun," Polk said. "I mean, it was still fun being out there with your team, but it was hard. I definitely don't want to do it again, but you just push through it for your team and you know your team is pushing through injuries, too."

Polk underwent surgery shortly after the season ended to repair his wrist. Doctors inserted three pins to help ligaments re-attach. They later removed the pins and Polk only recently gave the wrist his seal of approval after testing it at the bowling alley the night before Pac-12 media day in Los Angeles.

Training camp opened for the Buffs Monday and Polk spent his first day in his new No. 7 jersey after spending four seasons in No. 26. He said he made the switch because seven is a lucky number and it comes up frequently in the Bible.

The process of deciding which defensive backs will be on the field with Polk this season also began Monday as the Buffs try to improve on a pass defense that gave up 255 yards a game and 34 touchdowns.

Polk has been active in the offseason, organizing meetings with his younger teammates trying to teach them some of the nuts and bolts of the defense and how to be successful as a student. He said being a senior has given him a sense of urgency to take on such responsibilities without being asked by coaches.

"I remember when I was a freshman and I didn't know half as much stuff," Polk said. "If somebody would walk me through it, other than a coach, or take me aside and meet with me, it helped me out a ton.

"There is a sense of urgency and you feel this when you get into your last year. We've got to go. We've got to make a bowl game. Anything I can do to help out and get these freshmen coming along and ready to play, then I'm there for them."

Coach Jon Embree said Polk already seems like a big brother to Mosley, whom Embree believes is more likely to play this season after having spent so much time with Polk before camp.

It's possible Polk could be flanked in the secondary by other veteran players, but it's also likely that some of the freshmen will at least see opportunities if they don't win starting jobs outright.

Parker Orms has been unable to stay healthy to play much football in his three seasons in Boulder. Entering his junior season, coaches hope he can claim the strong safety position. Orms is a heady player who, combined with Polk, would give the CU defense its best chance of getting in the right calls on each play.

Defensive back Ray Polk answers questions during the weekly press conference at the University of Colorado in Boulder, Colorado September 27, 2011.
Defensive back Ray Polk answers questions during the weekly press conference at the University of Colorado in Boulder, Colorado September 27, 2011. ( MARK LEFFINGWELL )

Sophomore Greg Henderson set a freshman record for playing time at cornerback last season and if Jered Bell is able to regain his old form after missing last season with injury, it might be tougher than expected for some of the freshmen to get on the field.