The Redskins say they want to sign Joe Theismann to a new contract. He says he would like to return next season. But after the animosity that has built up this year between him and management, Theismann also concedes that he could be playing his last game in a Washington uniform Sunday.

On a day the Redskins' very slim playoff hopes ended officially with the New York Giants' dramatic overtime victory over Dallas, Theismann said, "If I had my druthers, I'd like to be back" in Washington next season.

"I've built up a relationship with Joe (Gibbs) and the things he requires a quarterback to do are essential to his offense," said Theismann, who needs only an average game against the Los Angeles Rams Sunday at 4 p.m. (WDVM-TV-9, WMAL-Radio-63) to break two major team season passing records.

"But I've learned that you don't get everything you want. I am just happy playing football. If I'm not back here, I can force myself to be happy elsewhere . . . I try not be surprised by any situation, whether it's a trade or whatever."

If Theismann isn't signed by the Redskins before Feb. 1, he will be a free agent, giving him the right to negotiate with other teams. But the Redskins, by making a qualifying offer to him, will reserve the option either to match another club's offer or receive compensation for him.

Since Theismann is making $225,000 a year, Washington would be entitled to two first-round draft choices, a burden another team is unlikely to pay.

Yet, Theismann will be no easy negotiator. He says he was hurt by the Redskins' refusal to sign him to a new contract before the season. Now that he is finishing off what he considers the best year of his career, he figures Washington will have to pay the price for its delaying tactics.

"They said in essence 'go prove yourself again.' If management says that, and they make you go through the mental anguish they put me through, then that should cost them more in the end.

"They gambled. If I fell flat on my face, I would have been hurt at the bargaining table. But I didn't, so I would think they have to pay the price. I don't know if they really cared if it affected me or not. If they don't care about me as a player, maybe that's their way of saying they don't want me around.

"I've lived through a very difficult year, and I'd be lying if I said otherwise. The whole contract situation affected me early in the season, but then I just decided not to be a little kid and pout about it. But I know that being a free agent is a farce. I'm selling a service. What's the demand?"

If the Redskins do sign Theismann, it will be a costly contract. With John Riggins already earning $300,000 a season, a new Theismann pact likely will be in the $350,000 to $400,000 range.

Whether Theismann believes that reflects his worth is another question. The contract proposal he submitted last spring reportedly was in the $500,000-plus area. Theismann's agent, Ed Keating, said that proposal would not have made his client the highest-paid quarterback in the league, but did call for a reasonable increase over his present salary.

And that was before this season, in which Theismann already has become the second-most productive quarterback in Redskin history. And if he throws 34 passes and completes 10 today, he will break two more of Sonny Jurgensen's club records.

Said General Manager Bobby Beathard: "I expect a tough negotiating period. How long it lasts, I don't know. But it probably won't be settled quickly, although I hope it is."

Said Theismann: "Over the past 11 weeks, I don't think any quarterback in the league has played much better than I have. It took four or five weeks to get everything coordinated. I was making some bad decisions that I'm not making now. I thought I was doing the right thing and I wasn't."

Theismann said part of the problem was that he watched too many films of the San Diego Chargers, where Gibbs served as offensive coordinator before coming to Washington.

"I saw films of Dan Fouts and I said I could do what he was doing. I said wow, I can toss the ball up like that and force things and still make big plays. But I'd try it and I'd get intercepted. I wasn't playing the kind of football I should have. I decided to be myself. I want to be consistent, every week, and not make mistakes. That's me, my style."

The Rams, who are 1 1/2-point underdogs Sunday, are aware what quarterback contract problems can do to a team. After losing Vince Ferragamo in a contract dispute to Montreal of the Canadian Football League, Los Angeles dropped out of the playoffs this season for the first time since 1972. The Rams (6-9) have made 13 lineup changes at quarterback in the first 15 games, but will again start Dan Pastorini Sunday.

"They've got a really physical defense, a big-time defense," Gibbs said. "And I think they'll come after us on offense with their running game, especially Wendell Tyler. We'll need to make some big plays on them or they'll try to stuff us."

Though the Redskins are eliminated, Gibbs said he'll play the game straight, going with his usual starters. "I'm coaching this to win," he said. "I intend to use Joe (Theismann). If the situation presents itself, then I might put in Tom Flick."

If the Redskins win, they will finish with an 8-8 mark in Gibbs' first season, which he says "is quite satisfying, considering our (0-5) start. And it will mean we have won eight of our last 11 games, which should give us momentum for next season. But don't expect the Rams to roll over and not play hard."