The Redskins must hear the doubters whispering, the voices saying that the strike-shortened schedule helped Washington as much as any team, that the playoffs will eventually puncture the team's euphoria.

Said Philadelphia Eagles Coach Dick Vermeil: "If the Redskins have a weakness, it might be that they'll come up against a team in the playoffs that has everything going for it that the Redskins do, but that has more talent. That would hurt them."

Of the seven games the Redskins did not play because of the strike, five would have been against playoff teams: Dallas, Cleveland, Pittsburgh, Cincinnati and Minnesota. But except for their 24-10 loss to the Cowboys, the Redskins have done nothing but win.

"They've done everything they've had to do," Dallas Coach Tom Landry said.

"There's no question the Redskins are improved, they're for real," Landry said. "Sure, they had an easy schedule, but then we did, too. The NFL arranges the schedule and the Redskins couldn't do much about the strike."

So why the doubts?

Perhaps one of the reasons some people are reserving judgment on the Redskins as they begin the playoffs today is that the team has not proved dominant on offense. In the last six games, the offense has scored only 10 touchdowns, four Sunday against St. Louis.

In recent weeks, especially against Dallas, the Giants and St. Louis, quarterback Joe Theismann's performance has dropped off from the spectacular level of prior games.

"But Theismann has continued playing at his level," said Landry. "When your team gains respect in the league, as Washington has now, you can't expect to do everything you want to do. The teams start looking for you, and they've been looking to stop Theismann more, too."

In the playoffs, as in the regular season, the team will be counting on Mark Moseley's near-perfect field-goal kicking and an unforgiving defense, the Redskins' best since 1974. So far that formula has been successful.

"Their defense has been really, really tough," said Giants quarterback Scott Brunner. "They have won a lot of games that they might have lost last year. They are blitzing a lot more than in the past . . . They don't do anything tricky; you know they are coming after you. But you still don't have time to get the ball to your receivers.

"The key to their secondary is that they put so much pressure on the quarterback. That's their gamble, that the pressure will keep the quarterback off balance and unable to throw."

Tenacity, not brilliance, has been the trademark of the Redskins this year.

"You can't say anything bad about them," said quarterback Doug Williams, whose Tampa Bay Buccaneers lost to the Redskins but went on to gain the playoffs. "They have played tough teams and have come away victorious, whether it be on the foot of Moseley, the arm of Theismann or the legs of (Joe) Washington."

Just the collective knowledge that the team could win also has been important. Last season, after losing their first five games, the Redskins won eight of their last 11. Landry believes that streak--more than any other factor--has propelled Washington's 1982 performance.

"It's a team thing," he said. "The team as a whole knows they can win and they play like they know it. It's hard to say what comes first, confidence or success, but they go hand in hand."

Much of that confidence is attributable to Joe Gibbs. The Redskins have responded to Gibbs' informal approach with an 8-1 record; the Associated Press responded to that record Tuesday by naming Gibbs coach of the year.

"The coaching has been the difference," said Vermeil. "(The Redskins) are finding ways to win games this year that they wouldn't have found last year."

"I think they came together this year," said Cardinals Coach Jim Hanifan. "Whenever you have a new coaching staff like they did last year, there's a period of time when everybody is feeling each other out. They've gotten that out of the way this season, and everybody knows their role. Everyone is secure."

"It's not a fluke year," said Doug Williams.