In those delirious days of early autumn, when the Redskins wooshed off to their fastest start in 38 years, players and coaches were constantly being asked, "How good is this team?"

When the question was posed to veteran defensive tackle Diron Talbert, his response was usually the same.

"I don't know," he would say every week as the victories and euphoria kept mounting. "I won't know until we lose a couple and see how some of these guys react. What's going to happen if things go bad? That's when I'll be able to tell you how good we really are."

Diron Talbert's season is over, cut short by knee surgery earlier this week. But for the rest of his Redskin teammates, now is the time to find out.

They should have the answer today in Dallas where the Cowboys are ready and licking their chops in anticipation of today's 3:30 p.m. kickoff. (WDVM-TV-9) at Texas Stadium.

The turkeys are coming, the turkey are coming, the turkeys are coming, the Cowboys have been gobbling all week, and the oddsmakers support their contention that the Redskins are stuffed and ready for carving.

Dallas is an 11-point favorite, even if the Redskins won the first meeting. 9-5 and the teams are tied at 8-4 for first place in the NFC East.

History also is on the Cowboys' side. The Redskins have never won both games during the regular season since the teams started clawing at each other in 1961, and Dallas has won five of the last six games in Texas Staeium.

Of course, the Redskins have been in these sort of precarious positions before. In 1977, they were 44 and won five of their last six. In 1976, they were 6-4 and won their last four. In 1974, they were 4-3 and won six of their last seven.

Pardee also knows a bit about adversity. His Chicago team in 1977 was 3-5 and heading nowhere before the Bears won their last six games and advanced into the playoffs, at the Redskins' expense.

The Redskins of 1978, of course, have lost four of their last six games and are floundering. They have been criticized by General Manager Bobby Bethand for not caring about losing, and fullback John Riggins has gone on record as predicting a massacre if his teammates do not get their heads together.

Still, in the last two days of practice, the Redskins seem to have recovered from their St. Lousi blues. Sessions Tuesday and yesterday were lively and spirited. One assistant coach described today's game as "my upset pick of the year. I can feel it. The Cowboys can be had."

Pardee agreed with the distinct posibility of an upset. "I think so, yes, the stage is pretty well set," he said. "We're had problems, they're had things going well for them . . . I think we'll be ready. I think we're ready for a good game.

"If everyone plays hard. I think we can knock them off. The big key to it is Tony Dorsett. When he's had a big day, they've won. Nobody stops him completely, but we have to control him, get them to go to the shotgun, and then defense that.

"Our offense has to have som success moving the ball, No. 1 to get points and No. 2 to get field position. You can't give them too many shots in close. We just need a total team effort all around."

Defensive end Coy Bacon, meanwhile, is steamed at some of the nasty things the Cowboys have been saying.

"I wouldn't miss this game for nothing," said Bacon, who has missed two days of practice with a sore hip and shoulder. "Those guys are talking all that trash down there, and they've been running their mouth a little too much.

"They can talk all they want, but I know all it does is make me play harder. I feel this team coming back together, I really do. They have a name for a games like this. It's called a street fight, and I'm ready for it."

So are most of the other Redskins hobbled lately by injury. Riggins now seems fully recovered from the sprained right ankle that forced him to miss the Cardinal game, and will start. Tight end Jean Fugett, a former Cowboy who says, "I really do get excited playing these guys," has been running free and easily all week after missing most of the practices before the St. Louis game with a sore knee.

Jim Harlan will replace Jeff Williams at right tackle after recovering from knee problems himself. He draws one of the day's more rugged assignment - keeping Too Tall Jones out of the Redskin backfield.

Second-year man Perry Brooks will take Talbert's place in the starting lineup at right tackle, although Pardee says the Redskins will use quite a bit of their 3-4 defense against a Cowboy team with the NFC's No. 1 offense. That would mena Mike Curtis will see considerable action. Pardee also indicated yesterday that cornerback Lemar Parrish would probably not play unless an emergency arises.

For both teams, there are incentives. A Dallas victory would assure the Cowboys the NFC East title if the teams were tied at the end of the regular season. A Redskin victory would give Washington the championship and the first round playoff bye that goes with it if the teams finished with identical records.

The Redskins obviously would like to duplicate their effort of seven weeks ago against the Cowboys on a night when they managed to move the ball consistently and were able to keep the Cowboys out of the end zone.

"We've got to do what you always have to do against the great offensive teams," said quarterback Joe Theismann. "We have to get the offense going and keep it going. We have to move the ball and not give them the opportunity to control the game. They've get great personnel, and the longer they have the ball, the better shot they've got to score.

"I said before our last game is Washington that game was a mini-Super Bowl for us.Well this game, it's the same thing, and maybe even more important.

"It looks like they've got their act back together, and they're always tough down there. It's the pivotal game of our season, there's no question about that."

Now, finally the Redskins will find out how good they really are.

The Redskins, are expected, signed nine-year veteran Bob Heinz to fill the roster spot left open by Talbert's knee injury. Heinz, a 6-foot-6, 260-pound defensive tackle, participated in yesterday's practice and made the trip to Dallas . . . Redskins were cheered by a sign draped on a nearby building down the street from Redskin Park. "When the going gets tough, the tough get going," it read . . . George Allen has been added to the CBS broadcast team . . . Cowboys have the NFC's highest-scoring offense with 269 points . . . They also own a 20-15-2 edge in the overall series . . . Redskins will be off for four days following the game, returning to practice on Tuesday.