The opening speech was brief, but inspirational. George Allen, Coach George Allen, greeted 43 free agent football prospects yesterday and immediately reminded them of how important their opportunity was.

"You ever heard of a guy named Herb Mul-Key?" Allen asked them. "He came to a camp like this we held for the Redskins one year, made the team, and later went to the Pro Bowl."

Allen, once again, was back in Washington. Now the coach of the Chicago Blitz in the newly formed United States Football League, Allen is searching the world for players.

The camp was by invitation only and many of the players already were under contract to the Blitz. "Last week in Houston we found two guys," Allen said. "We've already been to Columbus (Ohio), Phoenix, Indianapolis, Dallas and Milwaukee. We're going to Los Angeles next week. We'll probably screen about 4,000 people.

"But it's nice to be back here. It always is."

For the next three hours Allen tested the players (no pads, no contact) in speed and agility drills, as about 50 people watched from the stands at Gallaudet.

One man, Greg Singleton, held a copy of Allen's book, "The Future is Now." The bookmark was a $10 ticket from the Dec. 12, 1976, game between Dallas and the Redskins in Irving, Tex. Allen was then the Redskins' coach.

"It was the last time we (the Redskins) won in Dallas and the last time we went to the playoffs," Singleton said. "It took me and my best friend three days to hitchhike to Dallas. I haven't shaken his hand since that day. So I came here to shake his hand and get him to sign my book.

"I went up to him and said, 'Coach, you don't remember me, do you?' He said, 'Yeah, you were with a red-headed kid in Dallas six years ago.' He's great. It's great to have him back, even if he's not with the Washington Federals. Maybe the Blitz will be like Dallas. We'll have a new rivalry."

The possibility of a rivalry between the Blitz and the Federals excites even Allen.

"There's nothing official yet," he said, "but we're supposed to open the season here in Washington on national television."

Allen was asked how he felt about that. He smiled. He beamed. No words were necessary.

Dereck Lloyd, a free agent wide receiver formerly of Howard, said he'd like to treat Allen as just another coach, but that's impossible.

Meanwhile, Allen is preoccupied with times in the 40-yard dash, times in the cone drills, height, hands and such.

"We don't have many players in our area," Allen said, speaking of the USFL's regional draft setup. "We've got Northwestern and Northern Illinois. Out of 12 cities, we may have the fewest prospects."

And what if Allen should find some superstar, right in the Federals' back yard?

"We've been pretty aggressive going after free agents, so George is going to get his share," said Federals' President Jim Gould. "He creates a great amount of attention (for the league). If they find somebody that we didn't, fine. I don't feel he is treading on our turf. Anyway, it's tough to tame George. It's tough to keep him in bounds."