Troy

"It's tough watching any game, but it's a great spiritual learning process for me. It's very humbling. But it also gives me a sense of appreciation for what I do have when I am healthy. 

-- Troy Polamalu

Troy Polamalu is the wild-card of the 2013 Steelers' defense. 

At 32 years of age, will he once again be the whirling- dervish-disruptive-force-of-nature that he was in 2010, when he was NFL Defensive Player of the Year?  Or will he once again be the diminished shadow of his former self? ... the player of 2011-2012, bedeviled by chronic injuries (calf, Achilles tendon, concussions, etc.) that forced him to miss 22 games over the past four seasons and rendered him noticeably off his game even when he played.

When healthy, Polamalu is a great player. The Steelers need him to be great, and at full-speed, all season. They don't have enough talent, and not enough depth, to overcome any prolonged absence by him or diminished play. It's worth remembering that the 2012 defense had just 10 interceptions.

Troy Polamalu is 32 years old and, arguably, an old 32.

In an interesting piece that appeared recently on the NFL Network's website, Judy Batista wrote, "He found a new physical therapist, and they spent hours each day during the offseason -- he is still working twice a day during training camp -- attempting to break up the knots of scar tissue that have formed in his calves. In what might be best described as an extremely intensive and not-at-all-relaxing massage, the therapist kneads the clumps of hardened tissue that have formed around the small tears in Polamalu's muscle. The hope is that, as Polamalu endures the strain of the season, his calves will not tighten up again."

However ...

"I felt pretty good last preseason, too," Polamalu said. "I am feeling healthy as we stand here today."

It's pointless to worry about injuries that may not happen. As the late, great Elmore Leonard said, "Don’t worry about anything—unless you absolutely know what the outcome will be. People worry about things that never happen to them. You waste your life like that."

Nobody is potentially more valuable to any NFL team's defense than the Steelers' own Troy Polamalu.  He is the wild card.