The Redskins have been practicing the shotgun formation this week, an offense of last resort.

In obvious passing situations, the formation would give quarterback Joe Theismann more time to set up and read defenses.

Coach George Allen refused to comment on whether the Redskins had practiced the formation the past two days, citing security reasons. But he added the formation always has been in the Redskin playbook.

"We'd use it if everything else failed," one team source told The Washington Post.

Theismann has been sacked 18 times in the three games since he replaced Billy Kilmer as the starting quarterback.

"The big thing of the shotgun," Allen said," is that it's more difficult to rush. The quarterback is back seven or eight yards and he has a better chance to get the ball off and to read the coverage.

"It's a good formation, if you have a center who can snap the ball with a man on his nose, if you have a quarterback who can run and pass, if you have the type of personnel that fits it."

And that is exactly what Allen has: an offence that has been unable to pass-block effective recently, part of which is explainable by a quarterback who is less experienced than Kilmer, but is needed because the Redskins have been unable to produce a consistent running game.

What Allen also probably meant is that the Redskins would use the - shotgun under circumstanc such as the ferocious pass rush of the Dallas Cowboys the Redskins' opponent following Monday night's game against the Green Bay Packers.

The Redskins, according to offensive coordinator Charlie Waller, came out in the shotgun formation "about five plays last season, and we didn't GET A THING OUT OF IT."

The Cowboys currently use the shotgun more than any other team. Tight end Jean Fugett, who came to Washington as a free agent from Dallas, said CoWBoy coach Tom Landry used the shotgun in obvious passing situations because it afforded better pass protection.

Fugett said that in the Cowboy system at least three defensive linemen were double-teamed at the line of scrimmage, with a second line of blockers available.

Allen said practice had been closed yesterday to work "on a variation of a defense."

"If Green Bay is going to use the shotgun against us, would I love to know about it," Allen said. "All we're trying to do is protect our team and improve our chances of winning.

"It (the shotgun) is such a small things, there's nothing to it. It's like going to work on a fake punt. We might use it, and we might not use it."

Allen reported that fullback John Riggins was given the go-ahead to begin rehabilitation of his right knee, in a cast since he suffered ligament damage Oct. 16 against the Cowboys. A cast was removed earlier in the day.

"He got a good report and he'll be in every day," Allen said. "It's very encouraging; he's anxious to get back."

Rehabilitation normally takes two to three weeks, and team physician Stanford Lavine said "it will be several weeks before we know if he'll be able to play."

In another development, wide receiver Larry Jones was limping noticeably with a bruised knee suffered in a hit-and-run accident on his way to Redskin Park yesterday.

Jones told tha Fairfax County police that a dump truck ran him off Fox Mill Road near Herndon. His car came to a halt after spinning in a muddy field. He said the car was heavily damaged.

Jones, according to a club spokesman, also suffered bruised chest in the accident. He is expected to be available to play against the Packers.