Long after most of his Washington Redskins teammates had dressed and departed yesterday, linebacker Monte Coleman labored on a weight machine in the locker room, where only his occasional grunts broke the silence.

He concentrated on his left shoulder, pushing, pushing, pushing, until sweat dripped from his hair.

Coleman slightly separated the shoulder the day he returned from the strike, and now, a month later, it seemed as if he still was punishing himself and the weakened joint.

"If I hadn't worked at getting my body in shape and trying to improve myself physically, then maybe I could accept the injury better," Coleman said later. "But I tried to take care of myself and do the best I could to get better. And it still happened. You wonder what you must do to stay healthy."

Coleman has healed enough to again become one of the better pass-coverage linebackers in the National Football League. But he hasn't regained his spot on the starting defensive team from Mel Kaufman, partly because the shoulder isn't 100 percent and partly because his replacement has played well.

Coleman fears he will become typecast as a part-time player. Three years after he was touted as a potential superstar, he was sure this would be his breakthrough season.

Rich Milot knows the feeling. Last year, when a strained knee limited him to six starts, Milot wondered if he would remain a part-timer.

He got his answer this season. The coach of the linebackers, Larry Peccatiello, believes "Rich is the most improved player on the team. The guy has prototype linebacker size (6 feet 4, 235 pounds) and this year he is seeing things so clearly. He's following the development of the play, reading it right and attacking. He does the things you want from a guy who has all-pro potential.

"I talked to Richie and Monte a lot last year about the same thing. I wanted them to be more physical, more aggressive at the point of contact. I wanted them to take on runners and blockers and win the battle on the other side of scrimmage. This year, Rich isn't afraid to exploit his aggressiveness. He has confidence and he is making things happen on the run. He always was a good cover man. Now he's well-rounded."

Experience and a strenuous offseason weight program helped Milot improve from a one-dimensional player.

"I'm 10 pounds heavier than last year and I have to believe the extra weight and strength have helped," said Milot, who is third on the team in tackles behind Mark Murphy and Neal Olkewicz. "The way Pec wants us to play, to be reckless and make things happen by going after them at the line of scrimmage, you have to have strength. Since I'm tall, I can't rely quite as much on leverage, so I have to depend more on upper body strength to push off. Besides, I now know more about what's going on. I'm thinking less and reacting more. Everything is coming easier."

Milot and Coleman joined the Redskins in 1979, one a skinny, seventh-round choice from Penn State, the other an unheralded former safety from Central Arkansas. Jack Pardee was the coach, and the former stand-out linebacker liked what he saw in the two rookies. They and another rookie, Olkewicz, became his favorites.

"I've got to believe that if I was 100 percent, the left side would be mine and no one else's," Coleman said. "I'm glad I can contribute right now as a nickel-backer, but I don't want to be a part-time player, I want to be a full-time starter. I want it like Rich has it, in on every play. That's the only way I can achieve my goal, to be known as a great linebacker, so people recognize my name when I leave this game."

Coleman said his shoulder is "only 60 percent right now, so it's going to be hard to do much more than play pass defense this year. That's what troubles me. I knew what I had to improve on this season against the run. I wasn't reading runs right. I wasn't aggressive enough, the tight end would drive me off the play and I'd get hooked. I was looking instead of reacting."

Although Kaufman isn't as strong or as quick as Coleman, he has displayed good reactions against the run. He takes on tight ends and fights blockers. Peccatiello has been impressed.

"If Monte was healthy, we'd have to determine a starter on a game-to-game basis between him and Mel," Peccatiello said. "As a rookie, Monte was handed a very heavy, unfair burden: the potential to be a superstar. That's a hard thing to live up to. We'd just like him to relax, get well and not worry. He just has to have confidence that things will work out for him."