The ability of the Washington Redskins' defensive secondary to rebound from a surprisingly inconsistent exhibition season will depend greatly on whether cornerback Joe Lavender can improve.

Lavender, beginning his 10th professional season, has yet to play as well as he did in years past. He has had other so-so summers, then wound up being selected to the Pro Bowl, but there is concern now whether the years have taken a toll.

"I'm playing football, like I want to be," Lavender said. "My condition is fine and when the season starts, I'm going to be there. I'm not going to get into negative vibes about the secondary. There's no need for that, it's just speculation."

To make many of the Redskins' complex coverages work, Lavender must be able to handle his man-to-man assignments without constant support from a safety or linebacker. That way, help can be given to fellow cornerback Jeris White, who is weak in man-to-man schemes. Otherwise, there will be a major problem in the secondary, which plays as much one-on-one defense with its cornerbacks as any team in the National Football League.

"There is no reason to think we won't be all right, but you have to be concerned about our performance going into the regular season, since we haven't played well yet," said Richie Petitbon, the defensive coordinator and coach of a secondary that has been among the league's finest in recent years.

"Joe has to come. He didn't have the best of preseasons, but I've seen that happen to him before, so I'm not overly concerned. But he has to start being of value and getting better. We'll watch him closely, but I think he's in shape now. It helps him when it gets cooler. He plays better in cooler weather."

Coach Joe Gibbs, who admits the Redskins will have to limit how much man-on-man the cornerbacks play against some teams, said he was confident Lavender will improve. "We'll see, but he's always been there in the past. I'm not ready to panic about the secondary, like some people might tend to do. I'm sure it will play like it always has."

In four exhibition games, opponents completed 67 percent of their passes on this secondary, which limited foes to 47 percent last year, fifth best in the league. Just as alarming, receivers constantly were getting wide open.

"We purposely never had a detailed game plan, and that makes a difference," said safety Mark Murphy. "I don't think too much should be made of the exhibitions. We didn't use a lot of things that we will use in the regular season. We also function best with a detailed game plan, and that's what we'll have from now on."

Added Petitbon: "We were doing a lot of experimenting with schemes. We were more concerned about things other than pass coverage and, as a result, we left the cornerbacks in a lot of tough situations.

"Both safeties (Tony Peters and Murphy) are playing well. Peters had an excellent training camp. Vernon Dean is going to be okay. He improves every day and we will close the (experience) gap quickly, because he does what we want him to do."

For years, Petitbon's game plans have been designed to force opponents into passing, to play into the Redskins' strength, the secondary. This season, the defensive backs were asked to provide quicker support and more aggressive tackling against other teams' running backs.

Yet this is a secondary in transition. Lemar Parrish is gone, traded in the offseason to Buffalo, which cut him Monday. Dean, the second-round draft choice from San Diego State, is the nickel back instead of White. In the process, Lavender's role has taken on new importance.

At his best, Parrish was one of the league's elite cornerbacks in man-on-man coverage. He was so good that the Redskins usually left him on what he always called "my little isolated island."

Lavender now has taken up residence on that island. White, who plays better in zone schemes, has taken over many of Lavender's old duties. To give Dean time to mature, the Redskins need at least one more good season from Lavender. Otherwise, Dean will have to be promoted.

Petitbon hopes that an improved pass rush from his front line will help ease some of the secondary's burden.

When the Redskins have gone to their new situation defenses--the 3-4 on second and long, 33 nickel on third and long--they've put more pressure on quarterbacks. They usually accomplish that by blitzing at least one linebacker, which often leaves the cornerbacks in one-on-one coverages. Ideally, the team would benefit most if the linemen create the pressure, allowing the linebackers to help out on pass coverage.

The key to that ideal is Tony McGee, the defensive end acquired last week from New England. The Redskins have high hopes for right end Dexter Manley, but he needs McGee to complement him with a consistent rush from the left side.

Joe Washington officially was put on injured reserve yesterday and linebacker Quentin Lowry, cut Monday, was re-signed . . . The Redskins are considering a change in some of their situation defenses, replacing Larry Kubin with Monte Coleman as the blitzing linebacker. "We've talked to Larry about forcing his rush more and putting on more pressure up field," said Larry Peccatiello, the linebacker coach. "He understands we want him to be more aggressive."