It is that time during the pro football season when players and coaches search for labels to describe upcoming games. The Redskins, for example, have called today's 1 p.m. meeting at RFK Stadium with the St. Louis Cardinals everything from "must" to "crucial" to "really big."

Verbiage aside, the contest boils down to this for the Redskins: a loss would not eliminate them from play-off contention. But a defeat would create the same kind of problems that all but destroyed them at the end of the 1978 season.

A victory, however, would end a two-game losing streak. It also would provide a boost for the team's sagging confidence and justify Coach Jack Pardee's optimism about postseason play.

"Oh, if we don't win, it won't be the end of the year," said fullback John Riggins, the club's resident philosopher. "But we sure would be making it mightly tough on ourselves."

How tough would become clearer Monday night after the Eagles and Cowboys play in Dallas. Washington and Philadelphia are 6-4, Dallas 8-2.

So the sellout crowd in RFK Stadium (WDMV-TV-9) will be witnessing a home team fighting not only for a wild-card position but for some dignity, especially after last week's embarrassing thumping by Pittsubrgh. The Redskins are rated 3-point favorites.

To achieve both goals, the Redskins will have to control Ottis Anderson, the talented Carinal rookie running back who already has gained 1,000 yards and is aiming for his sixth 100-yard game of the season. He needs only 77 to become the Card's single-seaon rushing record holder.

But if teams concentrate too much on Anderson, St. Louis can burn them with quarterback Jim Hart and receivers Mel Gray and Pat Tilley.

Washington also feels it must regain the pass rush that took a day off against the Steelers. The Redskins still are searching for the king of offensive consistency that will score points while taking pressure off the defense.

To compound the Redskin problems, the Cardinals are flying high since whipping Minnesota, 37-7, last week, a victory they say gives a better indication of their ability than their lowly 3-7 record.

Washington (6-4) already owns a 17-7 victory over St. Louis this season, a triumph achieved despite 271 passing yards from Hart. The Cardinals gave up five grievous turnovers in that contest and allowed the Redskins to play their beloved ball-control, close-to-the-vest offensive style.

Anderson gained only 67 yards that Sunday in Busch Stadium. He and Hart couldn't solve a gambling Redskins defense that sent strong safety Ken Houston on a blitz 10 times on what Washington thought would be running plays.

Things have changed since then for both teams. Anderson is being used much more extensively in the St. Louis offense and the Redskins aren't nearly as efficient on offense.

"You have to be concerned first of all with Anderson," Pardee said. "They are going to him much more extensively than they were earlier in the season. Like Buffalo with O.J. Simpson and Chicago with Walter Payton, they've tailored some formations to take advantage of him.

"If they get off 60 plays, he'll handle the ball on 30 of them. That's smart. He's a good one, so why not get the ball in his hands a lot?

"But you can't forget about Hart and the rest of them. They'll be going long to Mel Gray quite a few times and Tilley (eight catches) hurt us in St. Louis, They've got the balanced attack you want as an offense."

The Cardinals should be better prepared to deal with the Redskins' blitz this time. Washington, which alters its defensive tactics each week, will continue to play a guessing game with the opposition quarterback, mainly because Pardee is convinced no team can alter its offensive scheme that much for one contest and still be effective.

"Sure, Hart has to be wiser about us than he was," he said, "but teams do certain things in offense to be successful and they stay with those things. It's up to the defense to counter them."

Even with the gimmicks, the Redskins' defensive success, as always, will depend heavily on the play of the fron four. Pardee says it is crucial for his team to mount a consistent pass rush while also shutting down the Cards' running attack and forcing Hart to pass.

"Our pass rush has to be better than it was against Pittsburgh," he said. "They have to be aware that we are applying pressure on the pocket."

Although Anderson gained 164 yards rushing against Minnesota, St. Louis is limping along the offensive line.

Both tackle Keith Wortman and guard Bob Young have been struggling with injuries and remain banged up for this game. The Cards also are starting a rookie tight end, Bill Burrell, at what continues to be a troublesome position.

The Redskins' major injury problem is cornerback Lemar Parrish, who has sore ribs. Pardee said yesterday Parrish would start, although Tony Peters has received most of the work at that spot all week.

Otherwise, Pardee was concerned mostly about an outbreak of flu which was affecting a number of his athletess. Quarterback Joe Theismann, the worst case, was sent home yesterday after Pardee decided not to work on the two-minute offense.

"Joe will be okay," Pardee said. "He could have played today if we had a game. We didn't want to take any chances with him and get him sicker practicing in the rain.

"We've had a good week, the concentration has been good and I think the players know what is at stake.

"This is an awfully big game for us. But over the last six weeks, they all will be. We are going to have to win our share, although we probably won't win all six.

"As the weeks click off, you start winning or you back yourself against a wall. Everyone we are going to be playing, including the Cardinals, are good teams. They are good enough to beat us. If we are going to make the playoffs, we have to beat those teams.

"If we have any division (title) aspirations, we have to win this game and the two with the Cowboys. But his is a good time of the season to coach. The players know what is going on so they have no problems getting up."

Pardee probably would be able to breathe a lot easier today if Theismann comes up with an especially outstanding performance. Washington's offense is at a point where its quaterback needs to provide a spark, much as he did against Atlanta earlier this season.

Although Theismann has not had particularly good games the last two weeks, he has been by far the steadiest part of the Redskins offense. Given time to throw against a Cardinal defense which surrendered 263 yards to Minnesota, he could be effective today.

"We got off to such a quick start the last time against St. Louis, it kind of changed some of our offensive thinking," Pardee said. "The when they scored on us in the second half, we came right back and scored.

"If we can avoid mistakes and take what they give us, we will be okay. It's going to be a tough game against a good team. It will tell us something about ourselves."

The weather forecast calls for rain but Pardee said wet conditions shouldn't bother his team. The Redskins have played in rain once previously this season, when they were trouned at Philadelphia . . .