John Williams remembers the day he saw his right leg again. How could he forget? It was so much thinner than the left.

"I knew I had a long way to go," he said. "There was a lot of doubt when I first got my cast off. When I first looked at it it didn't look too well. It was smaller in one part, and then the knee was very big, swollen, because a lot of fluids built up in it."

That was the state of the Washington Bullets that January day. Ruined. And how that knee responds to treatment now is a large part of the Washington Bullets' future.

It's been almost seven months since Williams tore the medial collateral ligament and partially tore the anterior cruciate ligament in his right knee, late in a loss to Utah. After that Dec. 2 night, the Bullets were 7-10. They finished the season 24-41 without him, winding up 31-51, the franchise's worst record in 24 years.

"I really didn't know how to take it," Williams said recently of the months of inactivity. "I had the cast on and really couldn't get around that much, couldn't get to the games. . . . I would just sit at home and watch TV, watch the games. That was the frustrating thing, sitting at home watching the guys run up and down the floor and the commentators talking about the players out there. I used to be out there running up and down the same."

Williams is now in Los Angeles, his home town. He is rehabilitating with Lakers team physician Steve Lombardo. His knee is coming along about as expected, and, based on similar injuries, he probably won't be available to Washington until well into next season. But that is not all that ails John Williams.

Just as he has to pare the rust from his knee, he has to pare weight from his body. What he weighs, no one will say. But it is significantly more than the 245 pounds he wants to weigh. Two-eighty? Two eighty-five? Two-ninety? No one calls the estimates out of line.

The extra weight is at the heart of a more troublesome issue. Just how good will John Williams allow himself to be? Few in the NBA doubt that a healthy Williams not only is the most talented player the Bullets have, but one of the most talented in the league. That player has shown up in spurts, highlight-long bursts in which he dominates a basketball game.

It leads to a potentially unsettling question -- does John Williams know how good he can be?

"It's a hard question," former general manager Bob Ferry said. "The game has been awfully easy for him, and when the game is easy, sometimes they don't realize how good they can be. I don't know what's holding him back. He's been very good. I just don't know how good he can be. I put him in a category of a reluctant star."

The Bullets are letting Williams go at his own pace. "According to the doctor in L.A., he's happy with the way he's rehabilitating his knee," said Coach Wes Unseld. "Neither he nor we are happy with his physical condition. My concern is that come November, John Williams be ready to play. That individual has to search for himself. I have no doubt that John will do that."

During the past season, people in the organization confirmed weights as high as 292 pounds, about 40 heavier than his playing weight, which was about 15 pounds heavier than the Bullets wanted him. The team enlisted the assistance of Brad Hatfield, a University of Maryland associate professor with a degree in exercise science who spent last summer helping Mel Turpin drop 24 pounds and, for much of the season, keep it off.

Williams will only say, "I've got a ways to go." But, before he went to the west coast, he talked about his weight problem.

"I'd like to see myself a lot thinner than what I am now," he said. "I've always had a weight problem since I've been with the Bullets. The knee's getting the extra weight and carrying it, and it's not doing my knee any better . . . Right now I want to get things back to normal as fast as possible so I can be ready for next year." Fulfilling Expectations

John Williams always has been about potential, a 6-foot-9 combination of finesse and power that made coaches palpitate with possibilities. From his early days at Crenshaw High in Los Angeles, when his coach, Willie West, tried to explain to nonbelievers that his best player really was that 10th-grader over there. And Willie West didn't play 10th-graders.

Williams was special at LSU and the Bullets were gaga with the possibilities when they took him with the 12th pick of the 1986 draft after his sophomore season. Small forward? Big forward? Even point guard? The potential combinations were mind-boggling.

"The problem in the NBA is that you're always labeled," Unseld said last season. "Once you get labeled, I don't care what you do after that, you're always thought of that way. People have given John the benefit of the doubt. Young, came out of school early, those kind of reasons for the way he's done things.

"Now, though, they're saying, 'Hell, this would be his second year out of college. If he's going to be a member of the elite, he's going to have to join the club.' I don't think you do it by figuring out how many points he scores. I think the only thing that John has to do differently is take up more of a leadership role."

This follows the NBA axiom that a great player generally starts showing his greatness -- defined as leadership, scoring, whatever -- in no later than his third season. Including early entries.

Williams earned a starting spot in training camp, showing occassional brilliance. In Washington's first 17 games, he averaged 18.2 points and 7.6 rebounds. The team was making that sometimes imperceptible shift in responding, listening, belonging, from one person to another. It happens to all contenders. The Pistons are Isiah's. The Celtics are Bird's. The Lakers are Magic's. The Bulls are Michael's.

Every Bullet respected Bernard King, Darrell Walker, Jeff Malone. But Williams was starting to take over. When you're 23 and healthy, that can be heady.

"Everyone who comes into the league gets in and they want to stay there," Williams said. "The easy part of it is going out there and playing, doing the things you know you can do. Once you're out there, then you think to yourself 'I'm here. I'm never going back to the way it used to be.' "

But then came the injury, in a close home game with the Jazz. The Bullets led by one point with less than two minutes remaining. King made a great hustling play, diving on the floor for a loose ball. Williams had to stop suddenly to change direction. His leg buckled under the sudden shift. He had arthroscopic surgery two days later. Preliminary diagnosis: out three months.

Williams couldn't run for three months, much less cut and move. Ask therapists who rehabilitate such injuries and they usually come up with timetables such as nine months to a year-and-a-half for total rehabilitation, depending on the severity of the injury. Ask John Williams's therapists, and they tell you the same thing. They speak in general terms about general injuries, because they don't discuss individual cases.

What Barbara Sales, the director of the rehabilitaton clinic in Bethesda, will say is this: "You don't come all the way back. I don't care what you do. That original structure is gone. You can try reconstruction and you can try to let it heal, and it may get to be 98 percent, but it's probably never going to be 100 percent."

Williams became a serf to the Cybex and Biodex machines that tortured his leg. An extra pound lifted or a second more of pain was a good day.

"Sometimes I try not to think about it," Williams said. "I really haven't sat down and gritted my teeth and said, 'Damn it, I wish I was healthy.' Things might have happened for a reason and I hope I can come back a lot stronger. . . . This is my job and it's something I enjoy doing very much. It's like I have to get myself back on track, get myself back together, get out there and do the job. It was like a learning experience for me, learning how to get my leg back together."

Larry Krystkowiak, the Milwaukee Bucks forward whose knee was severely injured during the playoffs in May 1989, went through a similar process. Krystkowiak missed the first 60 or so games for the Bucks the following season, but returned in March -- against Washington -- though he was hardly effective and was left off Milwaukee's postseason roster.

"The first two months were hell," he said. "I was in a cast and I had no control over my destiny. But from the time I got my cast off until today there's been progress every day. {Removing the cast improves} your mental aspect. It becomes much easier to make it. Instead of riding the bike or swimming the pool, you can play basketball. It's there. It's getting closer. That's what keeps you going."

For more instruction, Williams enlisted the help of King, who returned from one of the most devastating knee injuries suffered by an NBA player.

Williams said King "just tells me to take my time. You can't rush things like this. He said, 'Don't let them say when you're able to come back. You know when your knee is ready.' That made a lot of sense to me. The doctors and coaches, they can estimate when they think my knee will be back where it should be, but only I know that." The Road Back

In Washington, Williams worked out three times a week at the rehabilitation clinic, three times a week with Hatfield. The swelling is nearly gone. The idea, without getting too technical, is to find stability in the knee joint, then increase the strength along the entire range of motion the knee would endure in activity. The knee has to be able to handle stress on its weakest point as much as on its strongest. In a basketball player's case, can he stop, change direction, suddenly begin to sprint?

The stability in his knee is greatly improved. Strength has improved from the 40 percent at which Williams graded himself in April to 75 percent last month, Unseld said. Williams was supposed to be allowed back on the floor in June, but team doctors want him between 80 and 85 percent, Unseld said, before they'll let him on the court. That could happen this month.

Since going to Los Angeles, Williams has worked out five days a week, in a therapy group that includes the Clippers' Danny Manning. He recently ran two miles, Bullets General Manager John Nash said, adding that "assuming that he's still making good progress, it would be good to see him do some work in July on the court."

"It's gradually getting better and better," Williams said. "I feel my leg getting a lot stronger, working the therapy I go through. Now I see my wind is starting to come back a little bit. . . . I know what it takes to get my body in shape. As far as the leg goes, that's something I'm not real familiar with. I have to have help."

He says that now that he's running and lifting weights, he has "no doubts" that he will be able to come back. But the weight dogs him, continues to follow him everywhere and messes up the Bullets' plans. Unseld says he doesn't care where Williams works out, as long as he works out.

"We hope to see the weight begin to peel off," said Nash, who will be in California on other business this week but will stop in Los Angeles to have a look.

The Bullets are investing more than $1 million per year in their talented young forward. If he comes back reasonably healthy, they have a competitive look up front with King and recently acquired Pervis Ellison. They can put Williams at the power forward spot and leave him there, for the first time in his career. They could improve much faster than expected.

Said Ferry: "Having a weight problem at a young age is a really difficult problem. John can just balloon up on you quickly. It takes tremendous discipline, daily discipline, to control it. And it's very difficult. It's hard for John. He has to be on a diet every day, probably for his whole life. He has to change his lifestyle. And that's hard."