Another week, and still that doubt-filled blimp, with nothing more than a question mark written on the side, circles above the Washington Redskins' secondary.

"I don't think I'll be able to play Sunday," strong safety Curtis Jordan said yesterday. Jordan, who will be replaced by first-year player Ken Coffey if he doesn't play, was in only one short-yardage down in the Redskins' 23-13 victory at Philadelphia last Sunday because of a deep thigh bruise inflicted in the opener by the helmet of Dallas receiver Drew Pearson.

Now, the Redskins (1-1) will play Kansas City (1-1) Sunday at RFK Stadium. The Chiefs have an ebb-and-flow offense: the running game (an itsy-bitsy 82.5 yards-per-game average) ebbs and quarterback Bill Kenney makes the passing game flow (224 yards-per-game average).

"We figure they'll throw 40 times," said Richie Petitbon, coach of the Redskins' defense. "Maybe 50."

Which brings us back to the Redskins' secondary: "We've played well," said second-year cornerback Vernon Dean, "if you take away the few big plays we've given up."

"We're not crazy. We hear the people talking about us. We hear the coaches talking about us," said rookie left cornerback Darrell Green, who is replacing veteran Jeris White (still an unsigned holdout). "But we will put it together. It's a matter of time."

Ever since that 31-30 loss to Dallas, the Redskins have been a loose bunch. Their locker room pulse taps a light beat. Pete Cronan, captain of the special teams, kept smiling the other day, showing off his new eight-tooth denture span, which replaced an older, discolored span he had worn for years.

"The guys are proud of me," he jested. "Now they can't kid me about having green teeth."

Another day, Jordan showed up wearing a diamond earring in his left lobe, just to be different, and teammates gave the easy-going Texan grief. "Everybody gave it to me but Riggins," said Jordan. "I figure that's because he lived in Greenwich Village for two years."

Only when the subject is the secondary do the men of the Redskin world take a more serious locker room posture. Certainly, the secondary has improved over time. For the most part, it is young but confident.

Perhaps the most troublesome matter affecting the secondary is it follows last year's veteran, more hard-hitting unit, which rattled NFL skulls on a weekly basis.

Some numbers frame a picture of distress in the secondary: last season, the Redskins yielded 12 touchdown passes in 13 games. This season, they have yielded four in two games.

With Pro Bowl strong safety Tony Peters (facing sentencing on drug charges on Oct. 7) and White out of the lineup, and with Jordan seemingly out of Sunday's game, the Redskins will have only seven years experience in the four-man secondary: none by Green or Coffey, one by Dean, six by free safety Mark Murphy.

"Any time you don't have the same guys starting each week, it's unsettling . . . We'll just have to hope (the secondary) settles down," Coach Joe Gibbs said. "Except for those big plays, they have played well."

"The big plays we gave up were caused by blown coverages or by good offensive execution," Green said. Is the latter caused by inexperience, he was asked.

"I don't know, maybe," he said.

Right now, opposing quarterbacks are passing for an average of 225.5 yards per game. They averaged 179.3 yards during the regular season last year.

Certainly, the pass rush (eight sacks in two games) has been penetrating enough. But big pass plays by the opposition have hurt: Dallas' Danny White threw two touchdown passes to receiver Tony Hill (75 yards and 51 yards) in the third quarter of the opener to destroy a terrific first-half performance by the Redskins' defense, especially the secondary.

"We started out slow in the first couple games last year, too," Murphy said. Smiling, he added, "Maybe what we need to get our secondary going again is another strike."

Dean has been battling injury all season. Now, his neck is jammed. He was beaten for a touchdown by Hill and last Sunday, the Eagles' Ron Jaworski (who threw for 326 yards) threw a 27-yard touchdown pass to receiver Mike Quick, who also beat Dean.

"I made some mistakes last year," Dean said, "but they weren't as costly. I guess I have to take the bitter with the sweet."

"Last year, we had a veteran secondary and you knew that everyone would be in the right spots," Murphy said. "You can go over things on the blackboard, but without experience, it's tough . . . But I see improvement in this secondary. We're getting more experienced and we're learning how to adjust."

"People will talk, but they can't see what's really happening in the secondary from sitting in the stands," Coffey said. "You watch, things will even out. Pretty soon, we'll be making the big plays."

Riggins was back in practice yesterday, despite a slightly sprained ankle . . . Mike Nelms' punt-return average crept up to 15.2 yards (second in the National Football Conference) when a statistical change was made yesterday. Nelms caught a punt last Sunday with his feet already out of bounds. He had been credited with one return for zero yards on the play before it was erased.