CARLISLE, PA., AUG. 7 -- Just when the Washington Redskins thought their defensive line couldn't get any thinner, it did -- by one body.

Veteran free agent Alonzo Mitz was held out of most of today's work to give his strained groin a chance to heal, leaving the Redskins with only four completely healthy defensive linemen.

Line coach Torgy Torgeson, saying this is the fewest people he has ever worked with, said the move was a precaution and that he expected Mitz to play most, if not all, of Saturday's preseason opener against Atlanta in Chapel Hill, N.C.

At the moment the Redskins will line up with the left side of their line -- end Charles Mann and tackle Tracy Rocker -- intact. Rookie Kent Wells will start at right tackle, the spot that has belonged to holdout Darryl Grant most of the past nine years.

Plan B signee Pat Swoopes probably will start at right end. That's the end of the players who are completely healthy. Plan B signee Milford Hodge will play despite a broken hand.

Torgeson said Mann will get "just enough work to stay sharp" and that he expects Mitz and Swoopes to play most of the game at the ends. He said he pictures Mitz as an inside rusher in the future, but not until the ends heal.

No progress was reported on getting holdout Markus Koch to camp, and starting right end Fred Stokes is still nursing a sore shoulder. Stokes said the shoulder continues to improve a little at a time "and we're just going to have to be patient."

"The doctors say he'll be okay," General Manager Charley Casserly said. "It has taken a little longer than they thought, but it doesn't look like it's anything long-term." Conklin Throws Cautiously

There was encouraging news on one of the two injured quarterbacks. Rookie Cary Conklin took part in some of practice and even dropped back and threw some passes in controlled situations.

Conklin's right knee is still very sore and the Redskins believe he may have to undergo arthroscopic surgery. But that's a last resort Conklin would rather not face.

"It felt better," he said. "It's definitely getting better. I got some work in and that's encouraging. I'm hoping it's going to continue to improve. I know it's a lot more stable today and I was able to do more work. Let's see how it goes."

Meanwhile, Jeff Rutledge didn't practice and still had severe soreness in his right shoulder. Sanders's Hearing Delayed

Ricky Sanders's hearing on charges filed against him in connection with an incident at a Houston topless bar in May has been delayed again as the Harris County District Attorney continues to investigate. . . .

Running back Reggie Branch was reported doing well after surgery on his fractured right ankle at Arlington Memorial Hospital.