Cowboys at Redskins -- Week 17

Where: FedEx Field, Landover. Md. (grass, outdoors)

When: Sunday, 8:20 ET (ABC)

Spread: Redskins by 3

Forecast: Highs on Sunday will be in the upper-30s, but with the game being at night it’s likely temperatures will be in the low-30s by kickoff. As of now, there’s no chance of precipitation.

Records -- Redskins (9-6; NFC East 4-1); Cowboys (8-7; NFC East 3-2)

Past results: Two most recent meetings -- Nov. 22, 2012: Redskins 38, Cowboys 31; Nov. 20, 2011: Cowboys 27, Redskins 24 (OT). Series record: Cowboys lead 62-41-2.

What matters: The Redskins’ secondary. Though the defense has played better of late, they’re still susceptible to big plays. Missed passes have bailed out the secondary in each of the past four wins. But facing Dallas quarterback Tony Romo and receivers Dez Bryant and Miles Austin, the Redskins can’t afford to test their luck again. If Romo can move safety Madieu Williams with his eyes -- as he and others have done this season -- then big plays will follow. The Redskins must limit yards after the catch.

Who matters:  QB Robert Griffin III. He torched the Cowboys with four touchdown passes and 304 yards passing in the Thanksgiving Day win. But he was reduced to mostly passing from the pocket a week ago vs. Philadelphia after returning from a sprained knee. If Griffin is fully healthy, Dallas will struggle to defend the zone read option and ensuing play fakes. The Redskins hurt them in the first game with those looks, mostly on handoffs or passes as Griffin rushed seven times for 29 yards.

Key matchups: Redskins LT Trent Williams vs. LB DeMarcus Ware. With Williams’ left thigh still ailing, he’s susceptible to inside rushes. But Ware also is hurting because of a shoulder injury. Redskins NT Barry Cofield vs. C Ryan Cook. Cofield is playing well; his stunts in the first game helped apply pressure. Cook missed the first game with an injury but has made 10 starts this season. Redskins WR Pierre Garcon vs. Dallas DBs. Garcon burned the Cowboys with a 59-yard catch-and-run in the first game. If they lose sight of him or get out of their coverage lanes, Garcon will hurt Dallas again.

Injuries of note: RT Tyler Polumbus (concussion) and S DeJon Gomes (sprained MCL) both are questionable for Sunday. Polumbus missed last week's game at Philadelphia because of a concussion and was limited in practice Friday. However, coaches said Polumbus had been cleared to return by doctors. The coaches limited him because they want Maurice Hurt to be prepared just in case. Hurt started last week vs. the Eagles. Gomes suffered a second-degree sprain. He rotates at safety, playing more in coverage situations.

Inside stuff:  Nose tackle Barry Cofield’s play improved of late, largely because he’s finally comfortable playing the position. Cofield has a much better understanding of how to play certain blocks and what angles to take against various looks, knowledge he did not have last season. He’s also learned how to play with more patience after years of needing to play fast as a 4-3 DT. The result has been more disruption in the middle. 

Connections: Redskins DE Stephen Bowen played with Dallas from 2006-10 before joining Washington as a free agent. Redskins LB coach Bob Slowik was a Dallas assistant in 1992. Cowboys G Derrick Dockery played with Washington from 2003-06 and from 2009-10.

Stat you should know: Turnover differential has been a major reason for the Redskins’ success. They’ve tied a franchise record by playing a turnover-free game five times this season. 

Looking ahead: What’s next all depends on what happens Sunday. If the Redskins win, they’ll enter the playoffs as NFC East champions and receive a first-round home game. But they might clinch a playoff spot before kickoff. If Chicago and Minnesota both lose, then the Redskins would at least be a wild card. But if that doesn’t happen and they lose? They’ll be done as Dallas owns the tiebreaking edge over them based on record vs. common opponents.

Prediction: Redskins 30, Cowboys 28

John Keim covers the Redskins for the Washington Examiner. Follow him on Twitter @CBSRedskins or @John_Keim.