By Spike Eskin

PHILADELPHIA (CBS) – The 2012 version of the Pittsburgh Steelers are not your father’s Pittsburgh Steelers. The defense has been anything but a steel curtain, and they’re one of the worst teams in the NFL at running the ball.

That said, they get two very important pieces back this week in Troy Polamalu and James Harrison, and need a win pretty badly to stay alive in the AFC North.

I spoke with Neal Coolong (on Twitter @nealcoolong) of the great Pittsburgh Steelers blog Behind The Steel Curtain (visit Behind The Steel Curtain) about what sort of team Eagles fans will see dressed in black and gold on Sunday.

Spike: Polamalu and Harrison will be back in the lineup for the Steelers on Sunday, is it even possible to overstate how big that is?

Neal: On one hand, no, it can’t be overstated. To this point, the defense has been losing the majority of its 1-on-1 battles, especially up front. It’s not every play, but they’ve given up a slew of big runs (Darren McFadden’s long run in Week 3 was the difference between a dominant performance on the ground and a below standard one).

Having Polamalu and Harrison back – the team’s two best run defenders – gives them the ability to close off the edge, and to pursue sideline-to-sideline in a way they simply cannot without them in there.

On the other hand, if they aren’t 100 percent, they aren’t going to give the Steelers any more 1-on-1 wins up front than they’re currently getting. It’s not a certainty they’ll play yet, watch the practice report Wednesday through Friday. It wouldn’t be a shock if one or both of them doesn’t get through a practice.

Spike: The Steelers are next to last in the NFL in rushing yards, and averaging only 2.6 yards per attempt. Is the running game as bad as it seems?

No, it’s probably worse. Oftentimes teams with that low of a yards per carry are still getting a 15-plus carry here and there, and nullify that with a bunch of negative carries. The Steelers are getting literally 2.6 yards every time they rush the ball.

Their long carry of the year is 13 yards, and that came on an Isaac Redman run against the Jets in Week 2 when the replay showed his knee was down (the Jets challenged the play for the fumble Redman laid down but the call on the field stood). It honestly feels like the last time the Steelers ran for a big gain was when Rashard Mendenhall went 50-plus yards against Atlanta in Week 1 of 2010.

Mendenhall will likely be back Sunday after missing everything so far in 2012, as he recovered from a torn ACL at the end of last season, but odds of him cracking off a 50-yarder aren’t good, to put it mildly. We’re hoping he can crack off a five-yarder, though.

Spike: Ben Roethlisberger has always taken a lot of hits, but without a running game, it would same to get worse. Is he showing signs of wear and tear because of it?

Neal: Roethlisberger looks as sure-headed and strong-armed as he ever has. New offensive coordinator Todd Haley has centered the offense around his arm – as opposed to his legs, both in terms of mobility and tree-like strength to stand up with 280-pound defensive ends hanging on him. But that offensive center is around his ability to make throws in the shorter field, and not so much the 60-yard bombs the Steelers attempted frequently last season (with mixed results).

The good news is for Eagles fans Haley doesn’t seem to feel the need to shift play-calling away from a struggling running game. While Roethlisberger threw 49 times against an injury and talent-depleted Raiders secondary, they still had 26 and 28 carries against Denver and the Jets, respectively. They had 20 against Oakland. Those may only go for 1.5 yards a carry, but they are plays in which Roethlisberger doesn’t (nor shouldn’t) take a hit.

We’ll see how long Roethlisberger is able to continue his assassin-like play on third downs. That’s really the only thing keeping the Steelers competitive on the offensive side of the ball.

Spike: At 1-2, in a division with two 3-1 teams, it would seem like this game is as “must win” as it can get for the Steelers in the 5th week of the season.

I think for the sake of the fans (and hacks like myself) it definitely is. Climbing out of a 1-3 hole neither easy to watch nor fun to write about, especially in a division with two other good teams like Baltimore and Cincinnati. However, this team has been down Harrison and Polamalu for all but one game – the opener, which was in prime time at crazy, drunken Invesco Field. They were without Ryan Clark (their defensive MVP right now) in that game.

I do think, though, this team’s best games are ahead of it. Looking at it from a broader perspective, they have a new offensive coordinator, an offensive line that was supposed to be rebuilt, but midway through construction, it had to be brought back to its original unit. After all the off-season hype about the Steelers’ new offensive line, it’s four of the same guys, and Willie Colon (a veteran who missed the two seasons with injury) over Chris Kemoeatu at left guard.

The defense is working through Casey Hampton playing his way back into shape – he missed most of training camp and the off-season recovering from his own torn ACL. And without Harrison and Polamalu, it’s not a surprise the defense isn’t getting the splash plays its used to getting.

Oh, and that highly touted guard – David DeCastro – will be back around midseason.

I’d be worried about playing this team in Weeks 10-17. If they can stay at .500 by the start of Week 9, I think they’ll be the hot team ending the season and heading into the playoffs.

Spike: Alright, paint a picture of how the Steelers beat the Eagles on Sunday, and paint a picture of how the Steelers lose on Sunday.

Neal: The Steelers beat the Eagles Sunday by getting a cohesive and unified offensive effort to establish the run. Each individual offensive lineman is able to consistently win his 1-on-1s, and running backs are able to see and exploit running lanes to take some pressure off the passing game.

Defensively, the Steelers apply a firm and consistent pressure-based pass rush that may not yield sacks, but is geared more toward containing Michael Vick, making him throw under duress. The Steelers’ defense gets a sack or two on a third down or two, and gets a timely interception in the fourth quarter – the time of the game the Eagles have won in each of their three wins, and the same time the Steelers have lost in each of their two losses.

The Steelers lose by allowing Shady McCoy to run downhill while losing all banked hope that Andy Reid will seem to forget he’s on the field again. They further lose by Roethlisberger giving into the beating he’s likely to take against an active front seven, and trying to force passes down the field in frustration, thus putting the Steelers’ defense back on the field to deal with McCoy. Allowing Vick to throw in a clean pocket and not forcing him to do that thing when he starts burning through his progressions at warp speed and eventually making poor decisions with the ball.

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