The Washington Redskins added longtime defensive guru Bill Arnsparger to their coaching staff yesterday. He will work alongside defensive coordinator Mike Nolan in an attempt to improve the NFL's lowest-ranked defense.

Meanwhile, Redskins officials have begun discussions regarding a multiyear contract extension with the representative for running back Stephen Davis, the league's leading rusher and scorer. But Davis's agent, Steve Weinberg, said yesterday he believes the Redskins are moving too slowly and, thus, running the risk of Davis becoming an unrestricted free agent following this season. Redskins officials said they don't plan to attempt to sign Davis until after the season.

The Redskins listed Arnsparger's title as defensive specialist. He is scheduled to join the team Monday and, according to Nolan and Coach Norv Turner, will attend all practices and coaches' meetings. He will sit in the press box during games, and communicate with Nolan by headset, Nolan and Turner said.

"He's an experienced coach and he'll give us another set of eyes," said Turner, who denied that the move was a slap at Nolan. " . . . It's a chance to help Mike and help our other defensive coaches make us better."

Nolan once worked for the 72-year-old Arnsparger at Louisiana State, and Nolan said the two have remained close friends. Team officials said the Redskins have no plans to dismiss Nolan, but Nolan acknowledged that the decision to hire another coach amounts to an indictment of the defense this season.

"I want nothing more than to be successful, and I'll do whatever it takes," Nolan said following practice yesterday at Redskin Park. "If I have to bite the bullet on certain things, then I'll bite the bullet. . . . I'm not going to skirt that issue: We've struggled this year."

Nolan called Arnsparger a "close friend" and an "inspiration," and said: "This is as much my idea as anybody's. Nobody has put it on me. In fact, it's mostly my idea. . . . Just look at his record. He's always at the top, and rightfully so. He's always utilized his personnel extremely well."

The Redskins (3-1) have allowed 29.5 points and 433.5 yards per game.

According to team sources, owner Daniel M. Snyder pushed club officials to find a way to improve the defense but did not seek to fire Nolan. Turner did not want to dismiss Nolan, sources said, and Snyder assured Turner that he would not force the coach to fire any of his assistants during the season.

Arnsparger was doing fund-raising work for LSU yesterday and was not available to comment. He has been out of coaching for four seasons, but has an impressive resume. He has coached in five Super Bowls. He oversaw the Miami Dolphins' "No-Name Defense" in the 1970s and their "Killer B's" defense in the '80s. The Dolphins' defense ranked first or second in the NFL in nine of his 11 full seasons in Miami.

He has 39 years of coaching experience, 23 of them in the NFL. He was the defensive coordinator of the San Diego Chargers from 1992 to '94. In '92, the Chargers had the NFL's fourth-ranked defense, and in '93 they permitted a league-low 3.2 yards per rushing attempt and led the NFL with a plus-15 turnover margin.

He also has been a head coach, with the New York Giants and at LSU, and he spent five years as the University of Florida's athletic director. Nolan said he first met Arnsparger in 1980, and he served as Arnsparger's linebackers coach at LSU in '86.

As for the negotiations with Davis, Weinberg met on Monday with Vinny Cerrato, the Redskins' director of player personnel.

"We're in no hurry," Cerrato said.

Weinberg said from his office in Dallas: "Steve's off to a great start, and he's going to be an unrestricted free agent [in the offseason]. My general policy is, if a player wants to stay with the club he's with, do a long-term deal. The sooner we can get something done, the better it would be for everyone."

Davis steered clear of the matter.

"They're just starting up some stuff," he said. "I don't want to be part of it."

Davis, 25, is thriving in his first season as a starting tailback after beating out Skip Hicks for the job in training camp. He has 400 yards rushing and nine touchdowns, one rushing touchdown shy of Jim Brown's NFL record for the first four games of a season. He has helped the Redskins have the league's top-ranked offense this season.

The Redskins almost certainly will want to keep Davis beyond this season, in which he will make $934,000, and they believe he wants to stay here. His salary demand likely will increase if he becomes an unrestricted free agent and other clubs begin bidding on him.

The Redskins' previous regime lost last season's starting quarterback, Trent Green, by failing to re-sign him early. By the time team officials were ready to try to re-sign Green, they were prevented from doing so by the franchise's pending ownership change. Green signed a four-year, $16.5 million contract with the St. Louis Rams. The Redskins traded for Brad Johnson, and that has worked out extremely well for them.

The Redskins have room under the league's salary cap now. They would like to sign Davis after the season, but before he hits the free agent marketplace. However, Weinberg said that once Davis gets close to being an unrestricted free agent, he will test the market before accepting any offer by the Redskins.

Cerrato "said his time frame was December," Weinberg said. "But that's going to be too late. If it's December, our inclination would be to wait until the offseason and see what happens in unrestricted free agency.

"Steve would love to be in Washington. He wants to make a long-term commitment to the Redskins. He's on his way to having a terrific season. Each club has to start identifying the people it wants to have around in the future, and the Redskins have cap room."

Redskins Note: The Redskins announced yesterday that a limited number of new parking permits for Redskins Stadium would be sold to season-ticket holders on a first-come, first-served basis. The permits can be requested by calling the team's ticket office at 301-276-6050.