Who's going to chase the Dallas Cowboys?

If there is a theme for Sunday's 1 p.m. game at Giants Stadium between the Washington Redskins (3-3) and the New York Giants (3-3), that may be it.

To be sure, this is a high-powered game built on a 53-year rivalry. It matches the National Football League's best defense (New York's) against the league's best running game (Washington's) and one of the game's best young quarterbacks (Phil Simms of the Giants) against the league's second-best defense (the Redskins').

The Redskins have righted themselves by winning two games in a row. The Giants have wronged themselves by losing two in a row.

When these two teams lose, they do so the same way: by making turnovers. Last mistake loses.

This game should be a delight to watch. It most definitely stands on its own, with or without the presence, in mind only, of the NFC East-leading Cowboys (5-1).

But football players and coaches look at the standings, and since we're into Week 7 of the season, there's no way not to think about what this game means for the futures of the Redskins and Giants (and St. Louis Cardinals, too, who also are 3-3 and on a two-game skid).

"If somebody's going to chase Dallas, now's the time for them to step up and take a shot at it," Redskins Coach Joe Gibbs said bluntly the other day.

Both Gibbs and Giants Coach Bill Parcells, in his third full season in New York, say that something like an 11-5 record (the Redskins' record when they won the division in 1984) probably will win the NFC East this season.

That doesn't give anyone but the Cowboys much more room to lose.

Hence, the importance of this game. This afternoon, before they left Redskin Park for the airport, the Redskins activated center Jeff Bostic, who missed nearly a year because of reconstructive surgery on his right knee. Bostic will play a reserve role Sunday and will snap for the special teams.

As expected, the Redskins waived long snapper Doug Barnett to make room for Bostic.

Incentives will abound at the Meadowlands.

Redskins defensive end Dexter Manley, speaking to New York reporters during a conference call earlier this week, said the Giants' celebration of their 37-13 victory over Washington here last season was "an embarrassment to us on semi-national TV."

He took offense when nose tackle Jim Burt doused Parcells with a bucket of water near game's end.

"I remember they were having a good time on the sideline," Manley said.

Likewise, the Giants, who have not put together consecutive winning seasons since 1963, see the Redskins as the perennial team to beat.

Said linebacker extraordinaire Lawrence Taylor: "I like to play the Redskins most of all."

In the Giants' last two games, late fumbles have given Dallas a 30-29 victory and Cincinnati a 35-30 win.

In those games, Simms threw for 945 yards.

"It's been frustrating," Parcells said.

The Redskins' defense praises Simms as perhaps the finest quarterback it has seen this season, and is concerned about his ability to ignore the chaos around him in the pocket and find his receivers, Lionel Manuel in particular.

But Parcells points out Simms has fumbled four snaps in three games, including the one that led to the Cowboys' winning field goal.

But the Giants' defense hardly could be better. End Leonard Marshall (10 sacks) is getting to the quarterback more than Taylor, mainly because he plays on the right side with Taylor and benefits from the attention paid him.

This defense will tee off on quarterback Joe Theismann, who, despite two turnover-free games, still leads a passing attack rated 27th in the NFL.

Very few observers believe the Washington running game will roll the way it has the past two weeks, with John Riggins' consecutive 100-yard days.

George Rogers, back after missing most of last week's victory with a shoulder injury, is looking for something quite specific Sunday: a 100-yard game with no fumbles and injuries.

"I have had nothing but misfortune so far," Rogers said. "I'm gonna help this team sometime this year. There wouldn't be a better time to do it than the Giants, huh?"

There may be a tendency for some to believe the Redskins have turned the corner this season.

"Hey, we've only won three games," said defensive end Charles Mann. "We're just an average football team right now . . ."

So, it's with a fair measure of caution that the Redskins go into this game Sunday. During that conference call, Manley was asked if the Redskins would be able to stop the Giants' offense.

"Are we gonna stop them?" Manley repeated into the phone.

Theismann was sitting near Manley in the public relations office and overheard him.

"We're gonna try," Theismann shouted out.

"Hey, I've got a friend here helping me out," Manley said to the reporters.

"We're gonna try."