The Redskins began working yesterday on a double-tight-end offense, a move Coach Jack Pardee says he is making to compensate for the lack of productivity among his wide receivers and to help the running game.

It is far too early in the preseason to tell when or how often the Redskins plan to operate with both Jean Fugett and Jim Mandich in the starting offense unit. Mandich, the former Michigan man obtained in an offseason trade with Miami, has no reservations in explaining how the formation works.

"It's something I'm very very familiar with from my Miami experience," Mandich said yesterday. "We used it successfully against a lot of 34 defenses, which we're going to face in our first three games this season.

"We always felt you had to run the football to beat the 34, and this setup gives you a bigger arsenal to call on for the running game. In Miami, we would attack the flanks of the defense quite a bit: we'd go at the six hole off tackle and wider.

"I just think to win in the NFL, you've got to play great defense and you've got to control the football, run the football. You can't throw it 40 times a game and expect to win. I think that's why a lot of teams are adopting the system.

"There's no great secret to it. You replace a wide receiver with a bigger blocking tight end who may not be as mobile, but can be just as effective. It balances out your formation and it enables you to run to either side of the formation. It's no more complicated than that.

"In Miami, how we used it depended pretty much on the team we were playing, and also the condition of our own personal. If we had a couple of receivers banged up, we went to it. Sometimes we just used it as an element of surprise.

"Sure you can throw the ball from the formation. If you cram the ball down somebody's throat, it always makes it easier to throw. You'll catch the safety moving up closer to the line, things like that, and you can exploit it. You can use every pass-pattern in your playbook."

Against the Vikings Saturday night, the Redskins threw 30 passes, and only three were caught by wide receivers. In a rookie scrimmage against the Colts the week before, wide receivers caught only two passes. That sort of pattern concerns Pardee. And despite all the talk about a new look, multiformation offense, Pardee would be quite content to keep the football on the ground, as long as the Redskins keep coming up with the sort of numbers - 4.5 yards a carry - they produced in Minnesota.

Mandich, meanwhile, says he will do anything he can to help the Redskins, that the trade to Washington and his reunion with his former roommate, traveling companion and best friend, Jake Scott, "was the best thing that could have happened to me." He spent eight years in Miami.

"It was not a bad situation for me there," he said. "I still have a good relationship with them. But I was in the same place doing the same thing for eight years. So I played my option out last year with the understanding that I wouldn't be there this season."

For most of those eight years, Mandich was the man quarterback Bob Griese looked to for the critical catch, the game-breaking play. He owns two Super Bowl championship rings and scads of wonderful memories from the glory years of the Florida franchise.

But a year ago, Mandich was relegated to the third team in a Miami youth movement. He had only six catches, non for a touchdown, after grabing 21 scoring passes the previous five seasons.

His friend Scott had been traded to the Redskins in 1976, and "I just felt I needed a change," Mandich said. "I'm an intinerant at heart, a transient person. I know Jake was happy with the Redskins, and he thought the change had done him a lot of good mentally."

So Mandich talked about leaving the Dolphins with his coach, Don Shula, "and I do believe he accommodated me." The Redskins acquired him last May for two eighth-round draft choices and, says Mandich, "My evaluation of what it would do for me was truly accurate.

"I find myself enjoying the game out here. I'm just having a lot of fun again, which wasn't the case a year ago." But Mandich said he has nothing but the highest regard for Shula.

"Sure he had some good football players," Mandich said. "But it's more than that. He is extremely well organized, to the extent that two months before training camp starts he would tell you what you would be doing on the third afternoon practice of the second week.

"He's also a good motivator, he's got charisma about him, a real leader."

And how would be compare Shula to Pardee?

"I never like to make those kinds of comparisons," he said. "I'm just thankful the Redskins gave me an opportunity to play."

The Redskins waived offensive tackle Mike Horton, a free agent from UCLA, after Horton told Pardee he didn't think he had much chance to make the team and wanted to pursue opportunities in the Canadian League . . . Fullback John Riggins (sprained toe), running back Mike Thomas (stomach virus), cornerback Gerard Williams (bruised foot) and defensive end Duncan McCall (mild sprained knee) did not participate in yesterday's two workouts. All but McCall are expected to see action against the Packers . . . Lemar Parrish made another spectacular interception in seven-on-seven drills in the afternoon practice and seems fully recovered from his foot problems of last week. Pardee said he hoped Parrish and safety Jake Scott would be available against Green Bay.