The Washington Redskins, victimized for five touchdown passes by Miami quarterback Dan Marino in their 35-17 opening-game loss, say they have made virtually no defensive adjustments in their preparations to meet the 49ers in San Francisco Monday night.

The Redskins will be starting the same lineup except at defensive end, where Todd Liebenstein will be replaced by Charles Mann. Liebenstein, hospitalized for two days earlier in the week with a bacterial infection, was at Redskin Park briefly yesterday morning, but will not make the trip.

Liebenstein has lost more than 15 pounds since the last two weeks of training camp because of the infection, which has now settled in his right leg.

"I feel totally drained," Liebenstein said as he left the park before practice started.

After last week's game, Marino said he "couldn't believe it" when he saw the Redskins in one-on-one coverage on Mark Duper. The speedy receiver ended up with six catches for 178 yards and two touchdowns, including one for 74 yards.

San Francisco Coach Bill Walsh said earlier this week that he expected the Redskins to make some changes in their secondary, particularly in giving help to cornerback Anthony Washington. Redskins Coach Joe Gibbs and members of the secondary said yesterday, however, that no changes were planned other than to tighten normal coverages.

"We are going with the same guys we went with last week," Gibbs said. "We played good football with them last year and we think we can still play good football with them.

"It was a series of different things (that went wrong) against Miami. We had some mixups, but it was no particular person. We had coverages called -- good coverages -- but there was a missed assignment here and a missed tackle there."

Washington, a four-year veteran who became a starter late last year, said no actual changes were made this week in practice.

"I don't know what the problem was last week," said the 6-foot-1, 204-pound Washington. "There has been more intensity at practice this week and we have practiced hard, but as a defensive back, you have to ignore what happened to you the week before. You can't go out there for a game thinking about what happened. I write it off as something I don't ever want to happen to me again."

Washington will probably be covering wide receiver Dwight Clark much of the San Francisco game, often in single coverage.

"We aren't changing anything. Single coverage is something we've always done," said Washington, who is looking forward to the game. "It is in my home town. I hope they do come at me. Well, I know they are coming at me, but I look at it as a challenge. I've played against Dwight Clark before and he's always a problem, but (wide receiver Renaldo) Nehemiah is a problem too. They are all problems."

Safety Tony Peters said the Redskins will have to play much better against the 49ers than they did against the Dolphins.

"We could have played better against Miami," Peters said. "I know my performance was spotty. I could have reacted better. We know San Francisco may come with some of the same things Miami did to us, but we haven't made any changes. We just have to play better."

Gibbs said Vernon Dean, who lost his starting position to Washington, has played well, but continues as the fifth defensive back.

Liebenstein, whose leg was heavily wrapped from thigh to below the knee, was described as having "postinfection inflammatory arthritis." Gibbs said it is unknown when he will be available, but added, "I'm not worried about the depth. We've gone with six defensive linemen before."

Gibbs said Liebenstein's current problem is the aftereffect of the infection that has bothered him for almost a month.

"He has had a general body infection, and it is the type of thing that goes to any weak spot in the body," Gibbs said. "He got a bruised knee Sunday and that is where it ended up. If he had ended up with a bruised elbow, the problem would have probably settled there."