Joe Theismann always has wanted it this way. He always has wanted to make a spectacular splash in the National Football League and have all the accompanying adulation and fame.

He always has wanted to gain the respect of his teammates and have them relyon his abilities.

He always has wanted to shake off the label of "big mouth, little talent" that has plagued him since he left the sheltered life of being a football hero at Notre Dame.

Two years after wondering about his future in Washington, he now looms as the Redskins' most valuable figure. Without him, this club shrinks from being a playoff contender to an also-ran faster than Theismann can reel off a TV interview.

A year after critics waited for him to fall flat on his pretty face, Theismann has been told by his offensive coordinator, Joe Walton, that he has a chance to be not just good in this league, but great.

Nine months after enduring one of the most heartbreaking defeats of his career, Theismann has a twofold opportunity Monday night: he can help the Redskins avenge that loss to the Cowboys while also showing a national TV audience he is heir apparent to Roger Staubach's position as the NFC's best quarterback.

Theismann must play well in RFK Stadium for Washington to beat the Cowboys. He must play on the same plateau that Staubach occupied during his extraordinary career for Washington to make a run at any postseason honors.

"Joe is capable of being one of the best, I have no doubt about it," Walton said. "He's already reached one level. He did that last year by getting through a whole season and gaining confidence in himself while his teammates gained confidence in him.

"But I told him, 'Why settle for what you did last year? You can be better. You have the ability that few others have. It's up to you to use it and develop it.'

"I don't like to use the word 'great' very much. It's thrown around to describe too many people. But in Joe's case, I will. He's not there yet, but he can be. He can do for us what Roger did for the Cowboys."

Walton wondered in the offseason how Theismann would respond to his fine 1979 showing. Would he continue to work as dilligently? Or would his many outside interests distract him too much?

The answer came when Theismann showed up again during the late winter to review with Walton various game films and tactics. It was during these session a year ago that Theismann first grasped the role Walton wanted him to play in the offense. And it was during these sessions this time around that Walton realized Theismann was not satisfied with just one good season.

"If anything, Joe has worked harder this year preparing himself," Walton said. "We reached an understanding about his outside interests. I want him to do everything he can to better himself, but he always has to remember his first loyalty is to this team and his position."

It was Walton who convinced Theismann to switch from his "mad-bomber" approach of 1978 to the patient, percentage passing quarterback of last season. aAs Theismann grew, the offense grew with him. The Redskins scored at least 30 points in five of their last six games despite not having a breakaway threat at halfback or wide receiver. And the reason was Theismann, who picked apart defenses with his short passes, scrambled only when necessary and found that secondary receivers were as valuable as his prime targets.

"Joe, first of all, has the physical abilities you want in a quarterback," Walton said. "He has good quickness, a strong arm, a quick dropback, good techniques. He maybe isn't as tall as the ideal, but that hasn't hurt him very much.

"But a lot of quarterbacks in this league have even more raw physical talent. Joe is different because of the way he works and the way he has grasped what we are trying to do. He is making less and less mistakes all the-time. His reads and his decisions are getting better every week. That's the difference between success and failure.

"He responds well to pressure. Look how he runs the two-minute drill. Not everyone can perform like that under the same circumstances."

Walton's goal for Theismann is near-perfection. "I want him to complete 65 percent of his passes. He was at 59 percent last year, but the way we throw the ball and with the kind of accuracy and speed he has on the ball, there is no reason why he can't improve that mark."

The Redskins would like Theismann to become the dominating force of this Cowboy series, just as Staubach was the consummate throne in the side of Washington for so many years. If Theismann can handle the Cowboys, the Washington braintrust reasons, he should also be able to deal with the rest of the league.

With the lack of stability in the Cowboys' secondary -- Cliff Harris has retired, Charley Waters is limping, Benny Barnes is limping, Aaron Mitchell is inexperienced -- Theismann certainly has a chance to meet his coaches' expections Monday night. It seems unlikely Washington will run with that much success on the Dallas front four so Theismann's passing looms as the key.

Last December, when Staubach was bringing so much agony to Washington fans with his passing heroics, Theismann, too, was having a superior game. He completed 15 of 24 passes for 210 yards and three touchdowns.But he missed another scoring toss when a soft lob to Clarence Harmon in the second half was barely overthrown. A similiar pass by Staubach to Tony Hill won the game for the Cowboys.

In his career against Dallas, Theismann is 65 of 128 for 947 yards, five touchdowns, two interceptions and two touchdowns rushing. He has started five games against Tom Landry's team and has lost three.

"I'm comfortable and confident for this game," Theismann said yesterday. "I've been happy with my preseason (no interceptions on 66 attempts, 56 percent accuracy) and with the way the offense has developed.

"This has been a vastly different year for me. It's the first time that I've come to camp being able to concentrate on refining my abilities instead of trying to do something splashy to attract attention.

"There was no one hanging over my shoulder, threatening to take away my job. I needed a camp like that, so I could relax and not press every day out.

"There is no reason why I can't be better than I was last year. The guys around me are improved, we have Art Monk now as a receiver and the offense is more advanced. And I realized that I am only as good as today's performance. What I did last year was very satisfying but if I come out this year and mess up, then no one will remember what I did in 1979."

Theismann remains the outgoing, confident player he's always been, but his maturity on the field carries over to the way he conducts himself out of uniform. He's not quite as outspoken, nor does he see the need to build himself up as he did in the past. Now he can let his performances speak eloquently for him.

"Funny," he said, "I came into camp maybe taking a few things for granted. I just wasn't as sharp as I had to be. Joe Walton let it ride for a while, then we had a talk. I was lazy. I wasn't setting up as sharply as I should.

"I knew he was right. I didn't want to be complacent. It was good he kicked me in the butt. It woke me up."

Now, playing Dallas is all the kick Theismann needs.

"Anyone who can't use this game as reason to be prepared isn't much of a player," he said. "I think good things are going to happen to this team this year. And I want to make sure I'm part of what happens."

Staubach, Theismann realizes, didn't blossom as a bona fide star until he was in his 30s. Theismann will turn 31 Tuesday.

"I've got at least five more good years left," Theismann said. "I'm not pressing. Things are right on schedule. There is no other place I'd rather be than in RFK Monday night against Dallas. And I'm sure Roger would feel the same way."