Can the Eagles help spoil the playoff chances of the rival Cowboys? That's the goal tonight as Nick Foles and the Eagles take the field at Cowboys Stadium for an NFC East showdown. What matchups will determine the outcome? Who are the key players? Let's take a look ...

When The Eagles Have The Ball
The Eagles will once again roll with their rookie duo in the backfield as Michael Vick and LeSean McCoy continue to recover from their concussions. Bryce Brown needs little hype after his primetime performance last week in which he exploded for a franchise rookie record 178 rushing yards, including an electric 65-yard rushing touchdown. Brown's speed has been on display all season, but his performance in his first NFL start, and the first time in which he carried the ball more than five times in a game, was eye-opening. Still, there is some cleanup to do for Brown, who fumbled the ball away twice, a pair of mistakes that led to the Eagles' eight-point loss.

Nick Foles, meanwhile, wasn't asked to carry the offense last week against the Panthers, as he threw for only 119 yards on 16-of-21 passing. Perhaps not coincidentally though, Foles' performance earned himself a 76.2 quarterback rating, his highest of the three games in which he's received extended playing time this season. When he relieved a concussed Vick against the Cowboys three weeks ago, Foles was asked to carry the offense, as he threw 32 times, completing 22 passes for 219 yards and a touchdown. But Foles also threw an interception that was returned for a touchdown and was sacked for a fumble in the end zone that was also recovered by the Cowboys for a touchdown. For both Brown and Foles, protecting the ball will be of the utmost importance against a Cowboys defense that is only tied for 26th in the league with 12 takeaways.

As to who will be protecting Foles and blocking for Brown, that matter is not yet decided. We know that King Dunlap will line up at left tackle, Dennis Kelly will be the right tackle and veteran Jake Scott will take the reins at right guard. But with Dallas Reynolds hampered by an ankle injury, there's a chance that Evan Mathis, one of only two Eagles along with Brent Celek who will be making his 12th start of the season, will slide from left guard to center. If that's the case, 2011 first-round pick Danny Watkins will take over Mathis' vacated spot at left guard. Regardless of whether it's Reynolds and Mathis or Mathis and Watkins, the interior of the offensive line will have to deal with the Cowboys' interior linemen, not to mention the responsibilities of recognizing when and where the rush will be coming from, notably from DeMarcus Ware. Reynolds practiced Friday and is listed as questionable for the game.

On the outside, the wide receiver corps will be forced to deal with the absence of Desean Jackson, who not only makes plays for himself but opens up areas of freedom in the defense for his fellow receivers. The expected return of slot man Jason Avant will help, but Jeremy Maclin, Riley Cooper and Damaris Johnson will have to step up to help whoever lines up under center for the Eagles. Opponents have been wary of passing against a talented Cowboys secondary that includes first-round pick Morris Claiborne and free agent acquisition Brandon Carr. But that actually could be an area to exploit. Consider that the Cowboys rank ninth in the league with only 219 yards passing allowed per game. But there's a significant spread between that ranking and their ranking of 24th in allowing 7.2 yards per pass.

When The Cowboys Have The Ball

The Cowboys scored 38 points in the first meeting back in Week 10. However, the Eagles defense only allowed 17 of those points.

The critical play of the first meeting was a third-and-5 late in the third quarter. All four of the defensive linemen had a chance to bring down quarterback Tony Romo, but he escaped and completed a 25-yard pass to wide receiver Miles Austin. Three plays later, Romo connected with a diving Dez Bryant for the game-tying touchdown.

The Eagles struggled early in the game with the patented delay-draw runs that the Cowboys are notorious for. Dallas marched 80 yards on its opening drive and 30 of them were gained on the ground by Felix Jones, who also finished the drive with an 11-yard reception for the touchdown.

Credit the defense as the Cowboys offense only scored a field goal in the second quarter before the game-tying touchdown.

Romo finished the game 19-of-26 for 209 yards with two touchdowns for a 122.1 passer rating. Jones finished with 71 yards on the ground. Tight end Jason Witten had eight catches for 47 yards, while Bryant led the team with 87 receiving yards on three catches.

With 10 days to rest after their Thanksgiving loss to the Washington Redskins, the Cowboys will hope to have running back DeMarco Murray in the lineup. Murray has missed the last six games with a foot sprain and is listed as questionable.

Romo, meanwhile, has completed at least 70 percent of his pass attempts in three of the past four games. He has thrown seven touchdowns against two interceptions in that same four-game span. In the Week 12 loss to Washington, Romo threw for 441 yards and three touchdowns.

The time off should also help Austin, who injured his hip against the Redskins. He is second on the team in receiving yards (727) and touchdowns (4).

The Eagles will have a little bit of a different look up front. With the release of defensive end Jason Babin, Brandon Graham is now the starter opposite Trent Cole. Vinny Curry and Phillip Hunt should get additional playing time on the field.

The secondary struggled with big plays against Carolina and the previous week vs. Washington. Certainly, the Cowboys have the ability to execute the big play with Romo's athleticism and the likes of Bryant on the outside and Witten in the middle of the field.

The Eagles did a good job of holding the Cowboys offense to 17 points in the first meeting. They'll need a similar effort as Dallas still clings to playoff aspirations.

Key Matchups

Eagles' Defensive Line vs. Cowboys' Run Offense

The Cowboys entered the 2012 season looking like a dangerous and balanced offense. Running back DeMarco Murray was impressive, and quarterback Tony Romo was surrounded by more talent than at any point in his career. But Murray has missed the last six games, and his replacements have been more or less ineffective. As a result, this Cowboys offense has been about as one-dimensional as it gets. Dallas ranks dead last in rushing, averaging less than 68 yards per game.

The Eagles are allowing 117.5 yards on the ground this season, though they have not allowed more than 76 yards to a running back since Week 3. While the Eagles have yet to allow a 100-yard rusher this season, the Cowboys were able to find some success on the ground. The last time these teams met, Dallas' running backs ran for 102 yards on 24 carries.

However, the defensive line the Cowboys will see Sunday will look different than the one they played against in Week 10. On Tuesday, the Eagles released starting defensive end Jason Babin, replacing him with a platoon of young players in Brandon Graham and Vinny Curry. Look for the Eagles to shut down Felix Jones and the Cowboys rushing attack early.

QB Tony Romo vs. Eagles' Secondary

As bad as the Cowboys have been at running the ball, they have stayed competitive this season because of quarterback Tony Romo and Dallas' passing game. Romo is third in the NFL in passing yards with 3,357 and has tossed 16 touchdowns. But he has also thrown 15 interceptions and has been sacked 26 times.

While the Eagles' secondary has struggled in recent weeks, defensive coordinator Todd Bowles' unit will have to stop Romo and his plethora of receiving weapons if the Eagles hope to snap their seven-game losing streak. The Eagles secondary has been beaten on big plays recently, and hasn't been able to come up with any turnovers. Since Week 10, quarterbacks facing the Eagles have thrown eight touchdowns and no interceptions. It's a trend the Eagles simply must overcome to win.