The always interesting battleground game for Pennsylvania supremacy takes place in Pittsburgh on Sunday afternoon at 1 PM EST. The last time these two teams met in the regular season, the Eagles defense did a number on the Steelers offense, giving Philadelphia bragging rights. Of course, the Steelers finished that season as Super Bowl champions, so they got the last laugh.

This time around, it's an early season litmus test pairing teams on opposite sides of the .500 mark. At 3-1, the Eagles are alone atop the NFC East after last week's thrilling two-point victory over the visiting New York Giants. The defense has taken a big step forward in the second season under Juan Castillo and ranks fifth in the league in yards allowed per game and sixth allowed in yards per play. Offensively, Michael Vick and co. were able to get out of their own way last week, finally eliminating the turnovers and allowing the prolific offense to do its job – scoring on each of the their final five possessions of the game (not including the final-play kneel down).

For their part, despite their 12-4 record and playoff appearance, the Steelers are coming off a bitterly disappointing end to their 2011 campaign. Their season ended, of course, on a walkoff 80-yard touchdown connection from Tim Tebow to Demaryius Thomas in the opening round of the playoffs.  Now, the Steelers sit at 1-2, though they should be fully rested coming off their early bye week. Troy Polamalu, James Harrison and Rashard Mendenhall are all expected to return from injuries. History is working on the Steelers side too as the team has gone 6-2 through their first eight games in all five of Mike Tomlin's previous seasons as head coach. Further, the Steelers have not lost back-to-back games since 2008.

Of course, the Eagles won't be worrying about the past come Sunday afternoon. After all, who better to teach the Steelers some new history than their in-state rivals?

Last Time They Met:
September 21, 2008 – Eagles 15, Steelers 6

Correll Buckhalter's 20-yard touchdown reception proved decisive as the defense shut down the Steelers to the tune of 147 total yards. The last image came in the fourth quarter when the Eagles forced a safety as Ben Roethlisberger was called for intentional grounding in the end zone in the face of a fierce pass rush.

When The Eagles Have The Ball

The Steelers will have some familiar faces back in action when the Eagles arrive to Heinz Field this Sunday.

All-Pro outside linebacker James Harrison and strong safety Troy Polamalu will be back in the starting lineup after missing time due to injury. Certainly, those players will be welcomed back. The Steelers rank fifth in the league in yards allowed, but their scoring defense is tied for 21st allowing an average of 25.0 points per game. In their game before the bye week, the Steelers allowed 34 points in a loss to the Raiders. The Raiders have scored 33 points in their other three games, all losses, combined.

The Steelers use a 3-4 scheme designed by mastermind Dick LeBeau which will feature a lot of zone blitz concepts where a pass rusher drops back into coverage and a typical coverage man will rush the quarterback. The Cardinals, which tamed the Eagles offense two weeks ago, is coached on defense by Ray Horton, who is a LeBeau disciple, but has actually added his own touches to it. It will be interesting to see if LeBeau looks at what Horton did to attack the Eagles. The Steelers have blitzed on 56 percent of their third down situations this season. Those third-down blitzes have resulted in three of the team's five sacks.

Up front, the Steelers have an experienced defensive line but it would be fair to question whether the age is starting to catch up. At nose tackle, Casey Hampton is in his 12th NFL season and is a mound of a man at 6-1, 325 pounds. He's on the field for about half of the team's snaps. In his 11th season, right defensive end Brett Keisel is 6-5, 285 pounds. 2009 first-round pick Ziggy Hood is the starter at left defensive end. 2011 first-round pick Cam Heyward is the top rotational player up front.

The loss of Harrison, who has not played this year after undergoing knee surgery in August, has been most noticeable in the pass rush. With 58.0 career sacks, Harrison is fourth in Steelers history and the team has only amassed five sacks on the year, good for a tie for 29th in the league. Opposite of Harrison, LaMarr Woodley has been the team's best player in the front seven in 2012 with two sacks and a forced fumble.

In the middle of the defense, veteran middle linebacker Larry Foote has been back in the spotlight with the release of James Farrior. Foote had 12 tackles, a sack and a forced fumble in the Week 1 loss to Denver. It was the 17th game in his career with 10-or-more tackles. Lawrence Timmons is the other inside linebacker along with Foote. Can the middle of the Steelers defense contain running back LeSean McCoy?

At cornerback, Ike Taylor is the player who will most likely be shadowing DeSean Jackson. In their Week 2 win over the Jets, Taylor held Santonio Holmes to just three catches for 28 yards despite 11 targets. With Taylor likely on Jackson, expect the Eagles to try and exploit the matchup between Jeremy Maclin and Keenan Lewis. Maclin only had one catch in the win over the Giants, but should be healthier with another week removed from his hip injury.

Getting Polamalu back at safety after missing two games with a calf injury will be something for Michael Vick to account for. He will also be a weapon in the blitz game. Polamalu made the Pro Bowl for the seventh time in 2011. In the Week 1 game against Denver, Polamalu had nine tackles. Polamalu has 29 career interceptions and nine sacks. Opposite Polamalu is another good safety in Ryan Clark. The team's leading tackler in 2011, Clark is third on the team with 15 tackles despite missing the season opener. The Steelers rank 31st in the league in covering tight ends, according to Pro Football Focus. It will be intriguing to see whether the Steelers with Polamalu back on the field can contain Brent Celek.

When The Steelers Have The Ball

It seems that when the Steelers are on offense, the focus tends to always center around pressuring Ben Roethlisberger and his ability to, in turn, avoid sacks and create big plays. Roethlisberger has not been gifted with particularly good pass protecting offensive lines over the last few years – in fact, he's been sacked more than any other NFL quarterback since the last time the Eagles played the Steelers in the regular season in 2008. Once again this year, the Steelers rank toward the bottom of the league in sacks allowed per pass, and this week they'll be facing off with the team that led the league in sacks in 2011. However, the Eagles only have seven sacks through four games, in large part because the opposition has spent so much time focusing their resources on chipping and double-teaming the defensive ends.

But while Roethlisberger is under pressure often, he may also deal with that pressure better than any quarterback in the league. Ask any Eagles defender in the locker room this week what makes Roethlisberger such a tough opponent and they'll tell you it's his ability to extend plays. After all, it's pretty tough to bring down a mobile quarterback who, at 6-5, 241, is built like a defensive end. And though the Steelers expect Mendenhall to play for this first time this season on Sunday, the passing game remains the strength of the offense. The Steelers have averaged an anemic 2.64 yards per rush this season, dead last in the league. And yet, somehow, the Steelers have managed to lead the league in time of possession to this point in the season. Why? Because they've also had the best third-down offense in the game, having converted 56 percent of their third downs for first downs. No other team in the league has better than a 50 percent mark in that category.

Luckily for the Eagles, third down defense has been a strength through four games, as the team has held opposing offenses to just under a 27 percent success rate, good for third best in the league. It seems as though big moments have been a strength for the defense this year, actually. Anecdotally, the team has shut down end-of-fourth-quarter potentially game-winning drives in all three wins this season. And in addition to their third-down success, the Eagles also rank tied for fourth in the league in red-zone defense, which is all the more impressive considering that the team ranked in the bottom three of the league in that category each of the last two seasons.

So where will the Steelers put pressure on the Eagles? Make no mistake that Nnamdi Asomugha and Dominique Rodgers-Cromartie will be tested by the dynamic wide receiving tandem of Mike Wallace and Antonio Brown. Wallace will certainly pose a threat to the Eagles defense after his scorching 2011 campaign of 1,193 receiving yards and eight touchdowns, while  Brown somewhat quietly had 1,108 yards receiving himself. Last week, the Eagles assigned their cornerbacks to cover specific Giants wide receivers across the field, while Asomugha and Rodgers-Cromartie stuck to their respective sides the week before against the Cardinals. So it will be interesting to see what Juan Castillo and defensive backs coach Todd Bowles dial up from a coverage standpoint. Kurt Coleman and Nate Allen will also be tested in deep coverage.

Key Matchups

Eagles CBs vs. Steelers WRs

Through the first four games of the season, the Eagles have the best cornerback duo in the league. According to Pro Football Focus, Nnamdi Asomugha and Dominique Rodgers-Cromartie have each allowed catches on only 40 percent of passes thrown their way. For those scoring at home, that's tied for fourth-best in the league. In total, they have combined for an impressive 16 catches allowed through four games.

As big as those numbers are, the corners won't get a break Sunday against the Steelers' seventh-ranked passing offense. Wide receivers Antonio Brown and Mike Wallace form a potent combination. Quarterback Ben Roethlisberger likes to take his shots deep, and for good reason. Wallace is widely regarded as the best deep threat in the NFL, and Brown is no slouch himself – through three games both receivers have four catches of over 20 yards. Look for the Eagles to use their cornerbacks' blend of speed and physicality to limit the Steelers' dangerous wideouts.

TE Heath Miller vs. LB Mychal Kendricks

While tight end Heath Miller may not be piling up catches or receiving yards so far this season, he has proven to be reliable in one key area – touchdowns. Miller has scored four times in three games this season, tied for most among tight ends.

To stop him, rookie linebacker Mychal Kendricks will need to continue his sensational rookie season. Through four games Kendricks has done everything the Eagles could have hoped for and more. Last week against the Giants, Kendricks helped hold tight end Martellus Bennet to only one catch for 2 yards. Kendricks has played nearly every snap this season, and is allowing only six yards per catch when in coverage. He and the linebackers will look to end Miller's consecutive games with a touchdown streak this Sunday.

Players To Watch

RB Rashard Mendenhall

The Steelers are expected to welcome back running back Rashard Mendenhall this week against the Eagles. Pittsburgh is hoping his return from an ACL injury suffered in late 2011 will bring a spark to their 31st-ranked rushing offense, which also ranks dead last in total yards. Meanwhile, the Eagles are allowing fewer than 100 yards per game on the ground, news that does not bode well for the Steelers. It remains to be seen what, if anything, Mendenhall will be able to bring to the Steelers offense in his 2012 debut.

CB Brandon Boykin

Through four games, Brandon Boykin has not had the best start to his kick returning career, averaging only 19.1 yards per return, tied for 31st in the league. But the coverage he will face Sunday has not been much better. The Steelers are giving up 33.2 yards per return, also good for second-worst in the league. Boykin showed flashes of his returner ability during the preseason, and after making personnel changes this week, he should have his opportunities in the return game.