And what would you have thought if you'd been told on opening day that the Washington Redskins' defense would play Dallas without all-pro free safety Mark Murphy, without starting left end Todd Liebenstein, without linebacker Rich Milot and with right end Dexter Manley and strong safety Tony Peters possibly reduced by injury to playing in role situations?

"I'd have said, 'Can we play somebody else?' " said Curtis Jordan, starting free safety the last month.

"I'd have said, 'How are we going to beat Dallas?' " linebacker Mel Kaufman said. " 'Or for that matter, how are we going to beat anybody else?' "

But the truth is, that scenario is the limping likelihood for this Sunday at RFK Stadium, where the Redskins and Cowboys will play for sole possession of first place in the NFC East Division.

But the corollary to this same truth is, so far, the Redskins' defense has survived the shipwreck. Toss out the team's 0-2 start against the still-unbeatens (Miami and San Francisco) and forget all of those injuries that would have forced most defenses to disintegrate.

Over the past month, the Redskins' defense has stopped the New York Giants (30-14), the New England Patriots (26-10), the Philadelphia Eagles (20-0) and the Indianapolis Colts (35-7). These are hardly league powers. Yet, in an year in which league domination lies in the hands of a precious few teams, neither are these four teams (a combined 11-9 minus the four losses to the Redskins) to be considered stiffs.

"Really, I think we've only had three bad halves this season," said the defensive coach, Richie Petitbon, noting that matters began to right themselves in the second half of the 37-31 loss to the 49ers.

How is it, then -- in the face of all of the injuries -- that the Redskins defense has managed to hold opponents to an average of 7.7 points per game over the last month?

First, the defensive line has turned downright dominant, led by tackles Darryl Grant and all-pro Dave Butz.

"When the defensive line is healthy all the way across, you have guys who can pressure the passer and get upfield (to stop the run), too," said General Manager Bobby Beathard, who said this is the best defensive line the team has had since he brought his Redskins building blocks here in 1978.

Over the last four weeks, Redskins opponents are averaging just 52 yards rushing per game (the Giants and Colts were ranked among league rushing leaders). This has been due, in part, to players such as Butz and Grant and middle linebacker Neal Olkewicz and left linebacker Kaufman.

Opposing quarterbacks have been sacked 18 times in four weeks. This, after the Redskins had a combined two sacks against Miami's Dan Marino (he's been sacked only once in six games) and San Francisco's Joe Montana (sacked 12 times so far, third fewest in the league).

When Liebenstein (bacterial infection) was placed on the injured reserve list after the first game, he was replaced by Charles Mann, a 6-foot-6, 260-pound mountain of potential. "I'm a lot more confident this year," said Mann, a second-year player who has forced two fumbles and has 2 1/2 sacks this season. "I don't go out there worrying about making mistakes. I just let myself loose."

Toss in the fact that cornerback Vernon Dean regained his starting spot against the Giants, replacing Anthony Washington. In the four-game turnaround, Dean has made all six of the team's interceptions.

"Vernon's playing like a (1982) rookie again," said Petitbon. Added Dean, "I'm just trying to have fun again. I don't want to go out there and just try to keep bad things from happening like I did last year."

Chalk up the fact that Jordan, an eighth-year player, has handled the defensive signals and the hard hits so well, that one is left to wonder: if Jordan maintains his high level of play will Murphy (eligible to return for the Giants game on Oct. 28) regain his starting spot upon his return?

Also, newly acquired Tom Beasley has played consistently in Manley's injury-induced absence, just as one might expect from a veteran of seven seasons in Pittsburgh.

And when strong safety Peters was sidelined with an abdominal muscle pull last week, Coffey took his place and performed with a cool confidence against the Colts.

Take a bone chip out of the elbow of Milot, forcing the team's most versatile linebacker to miss the last two games, then move linebacker Monte Coleman from part-time duty on the left side to Milot's fulltime duty on the right. Then watch Coleman respond. Coleman is now tied with Manley for the team lead with five sacks.

"Somehow, it seems like there hasn't been a disruption with the defense. The confidence factor really hasn't been broken," said Coach Joe Gibbs.

When the Redskins' defense reached its lowest point of last season -- following a 48-47 loss to Green Bay -- the defensive players called a team meeting. Murphy and veteran end Tony McGee stood up and spoke. To break the building tension, the name "Pearl Harbor Crew" was created for the secondary.

The defensive players say they haven't held any team meetings this year and not merely because Murphy isn't around to lead the defense by the hand now.

"Last year, it always semed like we were chasing. We didn't like the fact our offense scored 47 points and we still lost that game. We needed to talk," said McGee, who, at 35, remains among the most respected Redskins players. "This year, we knew we had only lost two games. I think we all knew that we just had to concentrate more."

The reactions to the injuries differ among the defensive players. From the youth of Green, a second-year cornerback, comes bubbly bursts such as "The NFL is different than colleges in that everybody gets paid. If you're going to pay a second-team player, he's got to be able to fill in for a first-team player and play as well."

From the experience of Butz, now in his 12th season, comes reflection: "There may have been a time when Diron (Talbert) or (Bill) Brundige (former Redskin defensive linemen) may have been hobbling at the same time, but I don't ever remember our defense having so many injuries at once."

Manley has been upgraded to "probable" (75 percent chance he will play), according to trainer Bubba Tyer."I have a gut feeling he'll play," said Petitbon, who also said he thinks that Peters might be able to play, too.