Coach Mike Shanahan and the Redskins face division leaders — the Cowboys, Bears and Broncos — in their next three games. EZRA SHAW (GETTY IMAGES)

This week is not about the rivalry. When the Washington Redskins — refreshed from a bye week after finally winning a game — face the Dallas Cowboys on Sunday, it’ll be the start of what could be a knockout stretch for the Redskins.

A victory and a bye provide Redskins fans a two-week amnesia from the 0-3 start. It won’t take long, though, for fans to remember that Washington has no pass defense, quarterback Robert Griffin III is still healing and special teams are nothing special.

Beating Dallas would be about more than possibly leading the NFC East (which means nothing in October). It could rescue the Redskins’ season.

With Chicago (Oct. 20) and at Denver (Oct. 27) up ahead, Washington could skid to 1-6 if it loses to Dallas. Then, there are still games against San Francisco, Kansas City and Atlanta looming. Washington can’t expect to repeat last year’s turnaround from 3-6 to a division title. That was a once-in-a-generation streak.

Washington must reboot against the Cowboys, who are coming off a 51-48 shootout loss to the Broncos. Redskins defensive coordinator Jim Haslett was probably flinching while he watched that game on Sunday, knowing it showcased two of his next three opponents.

Cowboys quarterback Tony Romo won’t repeat the 506-yard passing performance he had against Denver, but Dallas has proven it can put up a lot of points.

The Redskins need shootout victories, given their awful secondary and systemic poor tackling. But so far, Griffin hasn’t been able to provide them. The game plan has kept him between the tackles, where the offensive line least protects. Griffin flashed his old agility against Oakland and is slowly returning to last year’s form, but it may take all season to get there.

It seems 2013 could be all about 2014, when Griffin will be healthy and the Redskins will have salary cap space to buy more than backups. Griffin needs this season to understand that the NFL isn’t about happy endings, it’s about overcoming knockdowns. Toughness in tough times is a bigger challenge than knee rehab.

Fans hope the rivalry with the Cowboys will inspire the Redskins to lift their play this weekend. In reality, players see it only as the next game. It takes a coach willing to interject hyperbole into midweek practices to maintain the rivalry. Coach Mike Shanahan probably enjoyed beating his former employer and longtime rival Oakland more than he would Dallas. He’d certainly enjoy beating another former employer, Denver, more than he would Dallas.

Sunday may be just another game, but it could define the Redskins’ season.