For the first time in Coach Joe Gibbs' six seasons with the Washington Redskins the team's players will undergo a preseason drug test, Gibbs said tonight.

The tests will be given "either this Tuesday or Thursday," Gibbs said. "I haven't decided which day."

The test, believed to be the first in team history, will be given at the Redskins' Dickinson College training camp. Results will be kept confidential, Gibbs said. He would not elaborate on specific details of the procedure.

Teams have permission to test players for drug use in training camp this year while the rest of National Football League Commissioner Pete Rozelle's random drug testing plan remains on hold pending a ruling in arbitration.

An arbitrator's decision is expected in September on Rozelle's plan, which calls for every NFL player to undergo two random drug tests a year.

The players' current collective bargaining agreement allows one preseason drug test and further testing if a team has "probable cause" to suspect a drug problem. That agreement expires after this season.

Although he is in favor of random testing, Gibbs said he had never asked his players to submit to a drug test until now.

"Before, I really didn't think that an announced test as opposed to a random test would be worthwhile," he said. "But the commissioner has stepped out there and is trying to do something positive. For us, I think it is time. We never have done it before, but I think it is time to support him in that decision."

Gibbs said he recently sent a letter to every Redskins player to announce his decision.

"I wanted them to know what I was going to do before I announced anything in public," he said.

Gibbs met with linebacker Neal Olkewicz, the team's player representative, before sending the letter.

Olkewicz confirmed that the players knew about the test. "It's no problem for us," he said. "The union conceded that point when Rozelle's plan went to arbitration ."

Gibbs and Olkewicz both believe a compromise drug testing plan should be worked out between NFL management and the players' union.

Gibbs reiterated that he will not give an opinion on the specifics of Rozelle's plan.

"Any problem that needs to be worked out is between the commissioner and the union," he said. "I believe this is a step in the right direction. I've been one of the ones encouraging them to get something going."

Olkewicz has said he believes NFL players are willing to discuss a new plan, but should be involved in its formation.

There was some confusion recently over whether the Redskins had taken a drug test before training camp. When Rozelle's plan was announced, Olkewicz said he believed the Redskins had been given a drug test in the May minicamp.

But Gibbs said that wasn't so, that, in fact, since his arrival in 1981, he had never asked his players to take a drug test.

Olkewicz said "it's always been assumed" that a urine test taken by the players included an examination for drug use.

"Maybe that's not so," Olkewicz said.

The drug issue has become a particular concern of Gibbs'. At the coach's request, Dr. Forrest Tennant, the league's new drug adviser under Rozelle's plan, spoke to the players for two hours during minicamp.

Gibbs said he believes strongly in a "tougher and more comprehensive drug policy" for the NFL, including random testing and "strict punishment."

"Let the players know if they get involved in drugs , they'll get caught," he has said on several occasions. "There are lives involved."

Gibbs said he does not think the "probable cause" provision in the current drug testing plan works.

"Doctors aren't around the players . . . the coaches are. And in my six years as the coach here, I can say that I can't tell."

The agent for veteran defensive end Dexter Manley said today he hasn't talked to General Manager Bobby Beathard in more than a week.

"I don't think they've shown much of an interest in making an agreement," said Richard Bennett.

Manley, who has not reported to training camp because of the contract dispute, wants about $450,000 to $500,000 a year. The Redskins' offer is about $325,000 for this season, but it might be getting smaller.

In a letter to Bennett, Beathard said the Redskins would reduce their offer by what is believed to be $1,500 a day, starting Saturday. That means Manley already may have lost $3,000.

"It doesn't matter because we don't have a contract," Bennett said. "What I'd really like to know is if the Redskins want him this season."

Second-round draft choice Walter Murray also remains unsigned. Murray, a wide receiver who is expected to fit nicely into the Redskins' offense, already has missed a week of practice.

"This is a serious problem," Gibbs said. "He's just flat missed a ton of work."

Kicker/punter Steve Cox agreed to terms with the Redskins, he said today. For now, Cox will work a majority of the time at kicker, said special teams coach Wayne Sevier. He is one of four kickers competing with veteran Mark Moseley. Cox will see double-duty as a punter, competing with Jeff Hayes and two free agents . . . Cornerback Darrell Green didn't report to training camp because his wife is about to have a baby, Gibbs said. Green is expected Monday . . . Quarterback Joe Theismann continued to decline comment on his departure from the Redskins. It's expected he will talk Wednesday or Thursday.