Even the satisfaction that comes from being 5-1 and virtually in the playoffs couldn't mask Coach Joe Gibbs' concern yesterday about the Washington Redskins' inability to score more touchdowns the last three weeks.

"We aren't scoring enough points to consistently win right now," Gibbs admitted. "We've been very fortunate the last three games.

"Our goal is to score 21 points or better every game and we aren't doing it. It's a concern. We have to score more . . . You have to have a big play (near the goal line) and we haven't been getting that. We've had field goals, so we haven't come away without anything, but we need more touchdowns."

Indeed, a major reason the Redskins are atop the National Football Conference standings is the marvelous field goal kicking of Mark Moseley. If he wasn't in the midst of the so-far second-longest streak of success in league history, his team would be scrambling for a playoff berth.

In the last three weeks, the Redskins have scored only two touchdowns, and one was on a 65-yard pass Joe Theismann threw to Charlie Brown. The only touchdown that resulted from a sustained drive in which the Redskins moved inside the opponents' 20--called the red zone by Gibbs--and then scored was on a 17-yard pass to Brown.

The Redskins want to score every time they get inside the 20, and this season they've been almost perfect from that standpoint. Nineteen times they've entered the red zone; 18 times they've gotten either a touchdown or a field goal from Moseley, who has kicked 15. Those field goals have been the winning margin in two of the three victories since the strike and all but one of the victories this season.

Sometimes, the Redskins deliberately call plays inside the 20 that will not jeopardize a field goal opportunity. They still strive for a touchdown, but only with high-percentage plays that likely won't result in turnovers. Because of the score of the game or the time remaining, the coaches feel it is essential in those instances to be more conservative, and help out their defense in the process.

But their inability to get touchdowns has made these poststrike games much closer than they should have been.

"It would be nice," Gibbs said, "to be able to play in the fourth quarter and not worry about hanging on. But I guess we are never going to blow anyone out."

Since field goals have been the difference in eight of Gibbs' 13 triumphs, he has little reason to be more optimistic. But because his offensive line is stronger and more experienced than last season, and because Theismann now has two good outside receivers in Art Monk and Brown, Gibbs had hoped for more touchdowns.

"We had lots of trouble scoring inside the red zone early last year," he said. "And we had improved on that until recently. We drove the ball over 60 yards three times Sunday and got inside the red zone and couldn't score a touchdown and that frustrated me. Our time of possession was up (from the previous week) and we didn't have turnovers, which is good. But not making the big plays was disappointing.

"If we can't get (the big play), you're hurting. We think we are better off than last year, but thinking you are doesn't mean anything unless you do it. And we aren't getting it done."

Since the Redskins' last efficient offensive showing, a 27-17 victory over the New York Giants the first game after the strike, they have had first downs inside an opponents' 30 eight times and inside the 13 four times. Twice, Theismann has thrown interceptions; five times Moseley has kicked field goals, and once Brown caught the 17-yard touchdown pass.

Gibbs said he did not think John Riggins fumbled in the final moments of Sunday's game, a turnover that gave St. Louis a final chance to win. "His body hit the ground and then the ball came loose," Gibbs said. "The rule says that isn't a fumble. But no one really was in a good position to call it. It would have been a heck of a way to lose."

In other matters, Gibbs said:

He is concerned about the number of long running plays being given up by the defense, which otherwise has improved noticeably since the strike ended.

Tight end Don Warren is playing superbly now that he has become a consistent threat to catch short passes. "He's playing as well as anyone I've been around," said Gibbs. Warren has caught 19 passes this season.

* The treacherous field in St. Louis has prompted him to review the type of shoes the Redskins are wearing. "I want to make a study," he said. "See what they wear in Canada. We had shoes for wet weather, maybe we should have worn them."

Riggins' fumble was the first lost by the offense since the first half of the opening game against Philadelphia . . . The Redskins are completing 64 percent of their passes, which would break the team record . . . Theismann has a touchdown pass in 13 of the last 15 games . . . Darryl Grant, getting his first pro start Sunday in place of Perry Brooks, was selected by the coaches as one of three standout defensive players; the others were Dave Butz and Rich Milot, who is playing the best of his four-year career . . . The Redskins have lost only two games in December the last four years . . . Until Sunday, when they were called for seven penalties, the Redskins hadn't picked up more than five in any game this season.