1. QB Philip Rivers -- With a sputtering running game and an ailing defense, the Chargers' hopes of upending the Cowboys likely hinge on their ability to win a shootout. Fortunately, Rivers looks more than up to the challenge. San Diego's red-hot gunslinger has completed better than 70 percent of his passes in four straight games, tossing seven touchdowns and no interceptions in that span.
Rivers plays to a fraction of the publicity of Sunday's counterpart, Tony Romo, because Dallas is a bigger market and Jerry Jones is equal parts owner and promoter. But if Rivers can will his team to another win, improving his all-time December mark to 16-0, his late-season success will be too much for the national media to ignore.
2. LT Marcus McNeill -- The player who protects the quarterback's blindside will always be in the spotlight. That's especially true when opponent features one of the league's best pass rushers, which is the case this week with DeMarcus Ware (nine sacks, three forced fumbles).
But the bigger concern regarding McNeill is his injured ankle, which he sprained in last week's win over the Cleveland Browns. McNeill was able to practice this week and will start against Dallas, but the bigger concern is his ability to finish. If he has to bow out, that will leave first-year lineman Brandyn Dombrowski to play left tackle and recent pickup Jon Runyan at right tackle. That would be a disaster against a Cowboys team that ranks in the top-10 in sacks (29).
3. DE Luis Castillo -- The Chargers were lucky Castillo's two-week absence coincided with a soft spot in the schedule. They're even luckier he's going to return this week, as Alfonso Boone is out with a knee injury and Ogemdi Nwagbuo is on injured-reserve due to an ankle sprain. With Travis Johnson (groin) also dealing with an injury, the only healthy, veteran linemen who were on the Opening Day roster are Castillo and Jacques Cesaire.
Castillo's presence will be a huge boost to a run defense that ranks No. 21 in the league. He will be tested immensely this week, as the Cowboys are one of just two teams to average at least 5 yards per carry.
4. CB Antonio Cromartie -- In close contests, the turnover margin decides the winner more often than not. And with Eric Weddle doubtful with a knee injury and Shawne Merriman hampered by a nagging foot sprain, Cromartie is the defender most capable of delivering a game-changing takeaway.
Cromartie has three interceptions in the last six games, although he has yet to score a touchdown this season after scoring four times between 2007 and 2008. If he can get a pick-six off Romo, who averages just one interception per 59 attempts this season, it would go a long way towards swinging the game in San Diego's favor.
5. P Mike Scifres -- The buzz began months ago regarding Scifres' appearance at new Cowboys Stadium: Will he boom a punt into the low-hanging video board? Tennessee Titans punter A.J. Trapasso hit the board during the preseason, causing a media stir and forcing the NFL to implement a do-over rule in the event it happens again. However, no one has hit the board in meaningful game.
Perhaps the bigger question is whether Scifres can handcuff Cowboys punt returner Patrick Crayton, who ranks fifth in the league in punt-return average (13.6) and who's already returned two punts for scores this season. Scifres has done a good job of this so far this season, allowing fewer than half of his punts to be returned (20 of 41) -- he must keep it up in Big D'.
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Michael Lombardo is a member of the Pro Football Writers of America and a long-time contributor to the Scout.com network. His analysis has been published by the NFL Network, Fox Sports and MySpace Sports. He has followed the Chargers for more than 15 years and covered the team since 2003. You can see more of his updates by following him on twitter.