One week, the running game breaks down. Another week, it's the lineman or the receivers who have problems. That's the most mystifying aspect of the Redskins' offensive performance this season: No one component has been consistently inconsistent.

The coaching staff never knows where the next problem is going to come. Just when one difficulty seems solved, another prevents the club from scoring effectively.

"I know it's corny and all," fullback John Riggins said yesterday, "but the little things are killing us. We've got to concentrate. I get tired of saying it and you probably get tired of hearing it, but it's true. The physical ability is there, but we've got to improve mentally."

Riggins paused. "I keep saying that every week," he said, "but sooner or later you run out of weeks. If we are a playoff-caliber team we have to concentrate and prove it.

"And I think this would be a good week to start."

This is the week the Redskins play the St. Louis Cardinals Sunday in RFK Stadium. Coming off two straight losses and with Dallas a game away, the Redskins realize they need a victory to enhance their playoff opportunities and end the threat of a potentially long winless streak.

A consistent effort from Washington's offense would greatly help their chances. The same attack that scored 27 points each of the first three weeks of the season has been limited to a total of 31 the last three. To take the pressure off the defense, a higher output is essential.

Coach Jack Pardee talks about "finishing off" what the offense begins. He believes execution isn't a major concern until the club nears scoring territory, especially inside the 20.

That's why the unit worked over-time yesterday on their inside-the-20 attack.

"We just need to get as familiar as possible with each other," Pardee said. "We cut down on individual work today and had more 11-on-11 work.

"You've got to rehearse during the week to do it right on Sunday. Once you get it down, you should be able to repeat it."

Riggins spoke of what he terms the "running game's failure to do its job most of the season. In the games we've won, with maybe one exception, we've run well. If we don't run well, we've had problems.

"We haven't made the other teams respect our running enough. If they respect us, they'll stack their defense against us to stop it and that will help our passing game. Otherwise, it makes it harder to pass.

"In my four years here, it seems to always be the same. An inconsistent offense. Everyone takes their turn, we all make critical breakdowns. If it was one guy consistently messing up, the solution would be easy: get rid of him. But that's not the case.

"Take one game. I miss a block on a linebacker and Benny (Malone) is tackled for a four-yard loss. Suddenly it's second and 14 instead of second and six, like we want it. That messes up your game plan."

Joe walton the offensive coordinator, talks of hard work and confidence. He says anyone expecting the Redskins to be explosive and to score a bundle of points every week just hasn't grasped what Washington's ball-control philosophy is supposed to accomplish.

"Oh, we could gamble and score more points probably," he said. "But we also would lose. We'd get burned as much as we would succeed.

"The type of game we play, we aren't going to score a lot of points normally. Our most glaring breakdown was against New Orleans, but we even moved the ball against Pittsburgh last week until things got out of hand.

"When we have won, we have controlled the ball, ground up the yardage and run a lot of plays. That's how we have to go about doing it. There are three ways to score a lot: you take a lot of chances, the defense and special teams give you great field position or you have super talent."

And the Redskins acknowledge they don't have Pittsburgh-like talent. They lack game-breakers at wide receiver and running back, so they don't have the benefit of striking often on quick, long-yardage plays. Instead, they are forced to drive methodically for scores, which in turn requires consistent execution and few mistakes.

"We rely on field position," Pardee said, "and we haven't had that good field position lately. That's one way to get you off to a good start when you touch the ball.

"We need better balance across the board from our wide receivers. One week, an individual breaks out, like when Danny (Buggs) had 10 catches and the next week Ricky Thompson may have a bunch.

"But we need better consistency from everyone. It's been something we've worked on from the start of training camp. And it's something we have to stay on all the time."

Improved play from the receivers becomes more important this week with the absence of Buddy Hardeman, the club's reliable third-down pass catcher. Hardeman was second to Buggs in receptions and his loss with a broken jaw will hurt.

"We just have to compensate for Buddy," Walton said. "Ike (Forte) has to come through, and I think he will.

"I don't think we ever run out of time to get better. You work at it and stress stuff and fill in the gaps when you have to. You just have to feel that you eventually will step out there and everything will come together."

"As we grow and mature and the talent increases the next few years, what we are doing now will more than hold us in good stead."

Of course so much of what the Redskins accomplish also depends on quarterback Joe Theismann, who is battling a flu bug that sent him home early from practice yesterday.

As long as Theismann continues his accurate passing and coolness under fire, Washington's power running and short passing strategy is a threat even if defenses know what to expect.

But if Theismann stumbles, the fragile nature of the Redskins' offense is threatened. As Pardee said earlier this week: "We don't have much margin for error. We want to do certain things well and if we do, we can score. If we don't, that's when we have problems."

Said Riggins yesterday: "We can't have anyone relasing, even on one play. That's when the breakdowns happen. If we can get enough people thinking on the same page at one time, we'll be okay.

"It's just unfortunate that this late in the season, we are still working on these things. Six weeks isn't that much time to get things right."

Pardee said he anticipates cornerback Lemar Parrish will start despite sore ribs but it still wouldn't be surprising to see Tony Peters open at Parrish's spot . . . Pardee cut practice short by about 30 minutes, saying that "we had a real good week and they are ready. We felt we worked as much as we had to."