It has been a week for rumors at Redskin training camp: John Riggins is to be swapped as part of a multiplayer deal; Washington it trading for the New England Patriot's Sam Cunningham, a deal is cooking to obtain Wilbur Jackson of the San Francisco 49ers.

As improbable as many of these suspicions may be -- Jackson had bad legs, Cunningham's agent is Howard Slusher, who is anathema at Redskin Park because of past dealings -- they do reflect a team-wide hunch that the Redskins are going to make some kind of trade, and soon, for a running back to ease the loss should Riggins not play this season.

Although Washington can deal anytime during the preseason, it seems probable that it would be within the next week. That would give the new player time to learn the offense before the opener against Dallas at RFK Stadium Sept. 8.

So while the Redskins begin their preseason with an 8 p.m. game Saturday in Baltimore, the scouting staff will be fanning out across the country, taking in the rest of the league's exhibition games and concentrating on running backs.

"We will be at every game and we will be looking at running backs," said General Manager Bobby Beathard.

"I can honestly say that we don't have anything going right now. We are just going to look at a few people that we might be able to do something with.

"I've talked to several teams who might have extra players in certain positions, and not just running backs. We need to know about all spots anyway, so if the coaches come to us and say they need a player, we have some names we can look at."

While Beathard played down the trade talk, another team source readily admitted, "If we are going to do something, we are going to have to do it pretty soon. We can't wait on John to decide what he wants to do. If we wait too late, and he doesn't come back, then we will be hurting."

Riggins, the team's best runner, is embroiled in a contract dispute that is keeping him out of training camp. He wants his contract's option year, which comes up in 1981, turned into a guaranteed $500,000 pact. He has told the team that unless it meets his terms, he will retire.

Of course, there is always the chance Washington will decline to get into the trading market, especially if the price becomes too high.

There has been talk for months that Buffalo's Terry Miller, a sensation in college, is available. Coach Jack Pardee, however, says he doesn't believe it is good policy "to take on other people's problems. If Terry is having trouble with the Bills, then maybe that's not a good way for us to go." h

Clubs such as San Diego and Cleveland have an abundance of backs, but the good ones probably are not within the Redskins' reach. Beathard also would love to obtain either Joe Cribbs (from Buffalo) or Jewerl Thomas (from Los Angeles), the two backs he wanted in the latest NFL draft.

The Redskins' thinking could be influenced by how well their own backs do against the Colts.

If the new starters, Clarence Harmon and Buddy Hardeman, are impressive and if reserve big backs such as veteran Don Testerman and rookie Ricky Claitt run well, then Washington might even be more cautious discussing deals.

The backs should get plenty of chances to run the ball. Offensive Coordinator Joe Walton warns that the Redskins are approaching this preseason much like they did the last one. They want to establish their power rushing game instead of coming out early with a fancy passing attack.

Last year, this philosphy resulted in low-scoring, dull contests that evidently accomplished what Walton wanted. By season's end, the Redskins were scoring as efficiently as any team in the NFC.

"I just feel you have to crawl before you walk," Walton said. "There is nothing better for an offense than to take the ball down the field on a sustained drive. They get the feeling they can move it and control the line. That's what we are after."

Joe Theismann will open the game at quarterback and play the first and third quarters. Kim McQuilken will replace him in the second and newcomer Mike Kruczek will take over in the fourth in a battle to see which becomes Theismann's backup.

Besides Harmon and Hardeman, who will play a half, the contest also will mark the debut of a number of other closely watched Redskins.

Among those are wide receiver Art Monk, the much-heralded No. 1 draft choice. Monk has been a pleasure to watch in training camp, especially when he catches a ball while cutting over the middle and has a chance to show off his running ability.

Monk and fellow rookie Zion McKinney, who also has had an impressive John McDaniel and Ricky Thompson. Two other veterans, Ken Harrison and Morris Owens, will be held out because of leg injuries.

Mike Nelms, the former Canadian Football League star, finally will have a chance to return punts, with last year's return specialist, Bobby Hammond, his backup. Nelms was made the No. 1 return man off his work in Canada but has yet to handle an NFL game-condition kick.

"I've been waiting a while for this night," he said.

This also will mark the official beginning of the punt-off between Mike Bragg, who has been on the Redskin roster longer than any other player, and former 49er Mike Connell, who has kicked well at times in camp.

"We want to look good but we also want to play a lot of people and get a chance to study their techniques and execution," Pardee said. "We are always out to win but we also want to accomplish our goals."

The Colts probably will use their regulars more than the Redskins will theirs. New Coach Mike McCormack needs to stir things up in Baltimore, starting with the rehabilitation of quarterback Bert Jones.

"The Colts seem like a more spirited team than the last two years," Pardee said. 'They are putting a lot more into their playing. I look for them to use their veterans a good part of the game. But that's okay. It will be good for us to go up against their best. It will give us a good picture."