The Washington Redskins face a task Sunday that they have been unable to consistently accomplish since George Allen made them a National Football League contender: decisively defeat a weak team.

The 4 p.m. (WTOP-TV-9) game finds the Redskins 10 1/2-point favorites over the Tampa Bay Buccancers, who have yet to win a regular-season contest in their 17-game NFL existence. While the Bues, 0-3 this season, have a good defense, they have yet to score a touchdown on offense.

Each year since 1972, the Redskins have managed to lose at least once to a weaklip [WORDS ILLEGIBLE] you've already fallen, 20-17 to the Giants this year - or have squeaked by against their so-so opponents.

Although Allen says this has been an up-and-down week of practice. Redskin players say they learned their lesson against the Giants.

"We're ready to strike," said middle linebacker Harold McLinton.

"We are aware of what has happened in the past," said wide receiver Frank Grant. "You can jive, say we beat the Cards and played a great game. But this year we lost to the Giants, last year to Kansas City . . . It's a matter of not saying. 'We can get it together and win in the last minute.'"

Even if left cornerback Pat Fischer and left defensive tackle Dave Butz do not play because of injuries. Allen said yesterday that his team is prepared.

But, he added, "If you aren't ready to play, doesn't help you."

"I don't think everybody is taking Tampa as lightly as most people think," said offensive left tackle Tim Stokes. "I'm playing against a great football player (Lee Roy Selmon). He's made some plays that are scary."

Stokes expects a low-scoring game against Tampa's 3-4 defense. The Redskins historically have trouble against the 3-4, and the past two weeks Minnesota's Fran Tarkenton and Dallas' Roger Staubach were able to lead their offenses to only one touchdown each against Tampa.

Tampa coach John McKay, who has not revealed whether he will start the immobile veteran Gary Huff or scrambling rockie Randy Hedberg at quarterback, said he is counting on his defense to keep the Bucs in the game.

"If you play good defense and the kicking game is in shape, you'll be there," he said.

The Redskins scored on their first drive last week against the Cardinals, their initial first-quarter touchdown in six preseason and three regular-season games.

If Washington can establish its offense and grab an early lead, then its defense will have more opportunities to exploit the risky plays of catchup football into turnovers that set up the offense for easy scores and a potential rout.

Although he missed the entire preseason and gained just 27 yards in the Giant game, running back Mike Thomas is now running at a pace that would enable him to surpass last seaon's 1.101 yards.

Thomas gained 87 yards against Atlanta and 88 last week against St. Louis. in 18 rushes each time. At that rate, he will gain 1,164 yards this season, including the first game. He gained more than 100 yards only three times last season, when he carried the ball more frequently.

McKay, who came to the pros after a successful career at Southern California, sees hope for his team.

"I think we're equal to most teams in many respects physically," he said.

"But beyond physical talent, this is a game of experience."

The Redskins have that. Washington's eight oldest veterans have more total experience than Tampa's entire 45-man roster.

One of those veterans, left cornerback Fischer, probably will not play. He aggravated a lower-back injury in practice Tuesday and, sources said. Allen wants to make sure he is available for Dallas, Oct. 16.

Allen denied this report today, insisting, "I would like to start Pat if he's ready. We don't save anybody for anything at any time. The only time you save somebody is when you have a playoff game (coming up) and the division is wrapped up."

Fischer did not make an appearance on the practice field today.

Asked why he did not practice, Fischer said, "It was raining. I'm not a mudder. I have a lot of horses that way, too."

Butz was on the practice field yesterday but he didn't take part in drills.

McKay said that running back Ricky Bell, the NFL's No. 1 draft choice this year, is very doubtful because of a shoulder injury. He will be replaced by Ed Williams, a three-year vet from Langston . . . Starting guard Jeff Wynans is out with a back injury and Steve Wilson will start in his place . . . Buc quarterback Huff and Hedberg have completed only 23 of 65 passes for 221 yards and five interceptions. The team is ranked last in the NFC in passing . . . Ed (Double O) Boynton, Allen's security man, is in traction at Arlington Hospital with a nerve problem in his lower back or pelvis and will miss his first game in 12 years . . . The Boston Globe does not think the Redskins will have a problem today, predicting a 41-3 victory for Washington, saying Tampa will be looking ahead to next Sunday's game against Seattle.