Joe Theismann will limp into RFK Stadium today and start as the Redskins' No. 1 quarterback against highflying San Diego. Still he's not sure how long his pulled hamstring will last against a Charger defense that leads the NFL in sacks.

So why is Theismann risking further injury in a game (1 p.m., WRC-TV-4) that hardly ranks as pivotal?

"I happen to like to play football," Theismann said. "I've always loved to buck the odds.

"I just forget what the odds are supposed to be for me and play. I just wouldn't play on it if it hurt too bad or if I thought the team was going to hurt by me being in there."

Yet Theismann admits he will be fortunate to escape without additional damage to the hamstring, which will take another month to heal even if the injury isn't aggravated further. But he says he isn't "playing around with a career-ending injury" so he doesn't feel he's taking a major chance.

Theismann also realizes that the Redskins, who have lost five straight, need him. Coach Jack Pardee believes the only way his team has a chance against San Diego, favored by 6 1/2 points, is with Theismann to provide the passing yards the offense has lacked the last two weeks. So he's gambling with his ailing quarterback, even though one sack might be all he can endure.

Theismann won't be nearly as mobile as normal. Instead of scrambling, he might have to absorb more punishment from the Charger front four. To avoid the rush, he will be asked to sprint out frequently, which will put more pressure on the hamstring.

"I'm not sure how I will approach things," Theismann said. "I'm not at full strength. The leg doesn't feel as good as it did before the Dallas game (two weeks ago). I'm just going to have to go and play things by ear." He reinjured the hamstring in the Dallas game when he was sacked near the end of the first half.

Some team sources believe Theismann shouldn't play again this season. If he is forced out today, he'll be replaced by Mike Kruczek, who started last week against Atlanta. With Kruczek in the lineup, Pardee has restricted the offense, hardly an endorsement o the backup quarterback. The Redskins, who gained a season-low 193 yards in the Falcon game, have scored only 51 points the last five games.

While the Washington offense has grown more conservative, San Diego's has become more wide open. Quarterback Dan Fouts has thrown for 3,868 yards -- Theismann has gained 2,297 -- and should go over 4,000 today for the second straight season.

Fouts, who Pardee thinks will put up at least 40 passes today, has accounted for 28 touchdowns this year and gone over the 300-yard mark in six games, tying his own NFL record.

He has three favorite targets: John Jefferson (69 catches, 1,147 yards), Charlie Joiner (60 cathces, 951 yards) and Kellen Winslow (72 cataches, 1,020 yards). Jefferson already has become the first receiver in NFL history to gain 1,000 yards in his first three pro seasons. Right now, he's probably the best in the league at his position.

The Chargers are confronting Washington at a time when the Redskin defense is playing its best of the season. The unit held Dallas to 14 points and Atlanta to 10, mainly because the front four has done a better job holding down opponents' rushing thrusts. But against San Diego, Pardee thinks the key will be how much pressure his woeful pass rush can muster.

"In the games they've lost, Fouts has thrown interceptions and has been under pressure," Pardee said. "Not necessarily getting sacked all the time, because he's tough to sack with his quick drop and release. But at least teams have not always allowed him to sit back there and throw at will. We need to keep harassing him." But Washington's best pass rusher, Coy Bacon, has been slowed by the flu and will not be 100 percent for the game.

The Redskins will try to confuse Fouts with a variety of defenses. "You can't give him only a few looks," said secondary coach Richie Petitbon. "He'll eat you up. They use the pass like a run anyway. Lots of five- and six-yard stuff. We have to be tough and aggressive and we have to execute well."

"We've got to force some turnovers, make them make mistakes," Pardee said. "He'll throw interceptions (18 for the year) and they'll fumble (18 lost this season), but only if you go after them."

But no matter how well the defense might play, Pardee realizes it won't matter if the offense can't score. And that means Theismann has to avoid tackle Gary (Big Hands) Johnson (16 sacks) and end Leroy Jones (12 sacks).

"Joe may be okay to throw," said one Redskin staffer, "but unless our line can keep them off him, so what? He may never get a pass off if we break down."