Interesting team, these Pittsburgh Steelers.

Is the defense too old? Will the offensive line hold up? Can key players stay healthy? Who is going to be the running back?

Answers to these questions and more may be answered sooner than we think.

The Steelers begin the 2012 season on national TV this weekend, facing the Peyton Manning-led Denver Broncos Sunday night.

The following week, they host the New York Jets and their two-quarterback system. And Pittsburgh is all too familiar with Tim Tebow.

If any quarterback can pick apart an aging defense, it’s Manning.

Casey Hamnpton and Brett Keisel up front, James Harrison and Larry Foote at linebacker, Troy Polamalu in the secondary — these guys have been around for a while.

Ryan Clark has, too, of course, but he won’t be playing Sunday.

LaMarr Woodley and Lawrence Timmons have to stay healthy, especially since Harrison’s health is already in question.

Key names for the Steeler defense this year are Ziggy Hood, Steve McLendon and Cameron Heyward. They need to inject some productive youth into that defensive line.

Offensively, the Steelers can throw the football. That’s no secret to anybody.

The secret Mike Tomlin and company are trying to keep is who’s going to be running the ball.

Rashard Mendenhall is healing from his knee injury well ahead of schedule and could see action in Denver. Isaac Redman ran for more than 100 yards against the Broncos in the playoffs last year and Jonathan Dwyer has been the Steelers’ most impressive running back in the preseason.

Who gets how many carries is anybody’s guess.

The Jets can stop the run, so where the Steeler ground game is at will be pinpointed rather early this year.

When David DeCastro and Mike Adams were drafted in the first two rounds by the Steelers last April, both were immediately projected as potential rookie starters.

Adams is No. 2 on the depth chart at right tackle behind Marcus Gilbert while DeCastro is out until at least midseason with a knee injury.

Willie Colon has been hurt the past two years and needs to stay healthy this time around. Max Starks is continually brought back because he’s still better than most linemen on the roster.

Ben Roethlisberger doesn’t need to be sacked 50-plus times again this season.

When it comes to special teams, the Steelers fired their coach during preseason camp and they have a new punter yet again. Chris Rainey looks electric on punt and kick returns.

The Steelers enter this season with a lot of question marks, probably too many to win a division title with.

Look for another wild-card push, however, with a 10-6 record.

John Enrietto is sports editor of the Butler Eagle