General Manager Bobby Beathard conceded that Washington's Super Bowl victory and competition from the United States Football League will make it more difficult for him to sign the 16 Redskins who became free agents yesterday, including fullback John Riggins, kick returner Mike Nelms and eight other starters.

"It would be naive to say we won't have contract problems," Beathard said. "We don't plan on losing anyone, but we have to prepare ourselves for the worst. By that I mean it won't be all peaches and cream. We're coming off a Super Bowl win, which makes everyone more optimistic about money. And the USFL evidently plans to be aggressive going after some players."

Even in these heady days following Sunday's 27-17 victory over Miami, there is concern in Redskin Park about the free agent situation. The Redskins remain in the midst of a building program, despite the NFL title, and are fragile enough to be disrupted by the loss of two or three key players.

Riggins, of course, has become Washington's No. 1 signing priority. He made $330,000 the past season and it likely will take at least a $500,000-a-year guaranteed contract to keep the big man, who, like all free agents, can negotiate with any National Football League team. But if another team signs him, the Redskins get two first-round draft choices as compensation.

At least two other players, Nelms and safety Mark Murphy, want substantial raises. Sources say Nelms' representative, Richard Bennett, already has talked to Tampa Bay of the USFL; not true, said Beathard.

Bennett refused to comment on that, but said Nelms will actively seek bids "from teams in and out of the NFL. Mike likes the Redskins, he has no complaints with them. But he is going to act as a prudent person would act, and that means looking into every avenue, including the USFL."

Murphy's representatives have held preliminary talks with Beath-ard. "We are very far apart," Beath-ard said. "We have a long way to go." Murphy led the Redskins in tackles the last four years.

"I want to play in Washington," Murphy said. "But I'd like some type of security in the contract. And I'd like to catch up for all the years in which I've been paid so low. I've always been the lowest-paid starter in the secondary . . . The USFL certainly is an alternative, but first I'd like to see the Redskins' attitude in negotiations. This can be worked out. I just hope being player representative doesn't affect things."

Other free-agent starters are linebackers Rich Milot and Neal Olkewicz, Pro Bowl safety Tony Peters, guard Fred Dean, tackle Joe Jacoby, defensive tackle Darryl Grant and cornerback Jeris White. The last time White negotiated with the Redskins, his agent, Howard Slusher, held him out of training camp and he did not sign until just before the last 1980 preseason game.

The remaining free agents are linebacker Pete Cronan, fullback Wilbur Jackson, defensive tackle Pat Ogrin, tight end Mike Williams, fullback Otis Wonsley and quarterback Tom Owen, who is a Slusher client. Jackson has talked about retiring.

The Redskins have 11 players entering their option year who either can sign a new contract or get an automatic 10 percent raise and become free agents in 1984: center Jeff Bostic, defensive tackle Perry Brooks, linebackers Mel Kaufman and Quentin Lowry, punter Jeff Hayes, receivers Alvin Garrett and Cris Crissy, cornerback LeCharls McDaniel, defensive end Mat Mendenhall, halfback Nick Giaquinto and safety Greg Williams.

The negotiations will be crucial to the Redskins, who would like to keep basically the same team makeup, and chemistry, that won it all. Beathard knows how quickly a championship team can be disrupted: he was with Miami when the Dolphins lost Larry Csonka, Jim Kiick and Paul Warfield to the World Football League, causing a decline never overcome until this season.

"We've got a good thing going and we want to make things even stronger," Beathard said. "You never can measure the USFL threat until they actually get involved, but everyone is aware it's there, and it increases competition. Most of the people who signed with the World Football League made a mistake. Players should look at more than dollar signs. This is a great town, with great fans and coaches. We don't have a reputation of being cheap, either."

How well they succeed in signing their free agents will partially determine whom the Redskins try to draft this spring. Their priorities then also will hinge on the health of running back Joe Washington, who plans undergo surgery on both knees in the offseason. The Redskins, who in the Super Bowl started nine players with two years or less experience--they have 20 on the roster--have eight draft choices, missing Nos. 4, 5, 11 and 12.

Joe Washington is confident he'll recover. But what if he doesn't and Riggins doesn't return? The Redskins then would be hard-pressed to be Super Bowl contenders again. And a running back would become top priority in the draft.

Beathard and Coach Joe Gibbs say they would like another pass-rushing defensive lineman, probably an end to complement Dexter Manley. They want another cornerback with talents mirroring those of rookie Vernon Dean. They want a linebacker, an offensive lineman who can play center and guard, a tight end who can go in motion and even a wide receiver with great speed.

Said Beathard, who two years ago ventured it would take the Redskins at least three years to become a consistent playoff contender: "We need to keep adding talented players through draft choices. If anyone thinks we have arrived, we are in trouble. Complacency will kill us."

Among those on injured reserve who could help next year are running back Reggie Evans, safety Ken Coffey, linebacker John Schachtner, linebacker Stuart Anderson and tight end Mike Williams . . . Murphy said he felt "embarrassed" Sunday for Miami quarterback David Woodley. "He just didn't know what to do," Murphy said. "We took a chance by doubling their tight ends and backs in our nickel coverage and leaving single coverage on the receivers. But for one game, it confused him. He didn't know how to adjust."