Harrison hasn't had much to do during training camp. (US PRESSWIRE)

Last season, after a Week 1 thumping at the hands of the Ravens, NFL Network's Warren Sapp called the Steelers' defense "old and slow." It's a meme that took on a life of its own, even as the unit improved. It continues to this day despite an offseason that saw the release of Aaron Smith and James Farrior, and a legitimate commitment to getting younger.

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Still, despite the likes of Ziggy Hood, Steve McClendon and Cam Heyward on the defensive line; Lawrence Timmons and LaMarr Woodley at linebacker; and Keenan Lewis at cornerback, there are positions where age remains a concern. Primary among them: outside linebacker where James Harrison, 34 years young, has yet to take part in training camp because of a balky knee.

In fact, according to Harrison's agent, Bill Parise, one of the Steelers' most menacing players could be facing arthroscopic surgery.

“With the exception of this little knee thing, James is probably healthier now that he’s been in three years,” Parise said according to the TimesOnline.com's Mike Bires. “He’s extremely fit. He just has to get this irritation behind his knee cap cleared up. That’s what’s causing the swelling, and (the Steelers) just want to get rid of that. So we might even look at doing a scope of that to get it cleaned up. We’ll just have to wait see how it plays out.”

Harrison's currently on the physically unable to perform (PUP) list but Parise thinks that could change either this week or next. Then they'll see how Harrison's knee responds to practice, and if the swelling continues, arthroscopic surgery could be an option.

“If it doesn’t respond the way everybody wants it, that sounds like the alternative,” Parise said. “We’d probably opt for that sooner than later.”

The thinking: Harrison hopefully would have time to recover in time for the Steelers' regular-season opener against the Broncos. Frankly, that sounds ambitious. Dolphins quarterback David Garrard underwent arthroscopic surgery last week and the timetable for his return is in the 4-6 week range.

If Harrison isn't ready by September 9, the Steelers could turn to second-year player Chris Carter, who capably manned the position in the team's first preseason game against the Eagles. A converted defensive end out of Fresno State, Carter has been impressive in training camp. He also seems unconcerned with the possibility that Harrison might be sidelined when the season starts.

“James is fine,” Carter told Bires. “You know, he does his thing. James is the consummate professional. He knows what he needs to get his body just right. I have no concerns about James.”

Parise added: “At this time, James is looking to play in the opener. We all think James will play in the opener.”

One person who'd be fine not seeing Harrison: new Broncos quarterback Peyton Manning.

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