The Boston Celtics' interest in free agent Bernard King waned in part because of medical reports that questioned whether the veteran forward's surgically repaired right knee could withstand the rigors of a full NBA season, according to Celtics team sources.

However, a physical therapist who worked with King from the time of his injury in March 1985 until his return to the court last April, said yesterday she would anticipate an almost total recovery for the player.

The Bullets have signed King to an offer sheet, and are hoping to work out compensation with the New York Knicks that would allow him to play in Washington this season.

"The injury is over, he has his strength back, he just has to play basketball," said Dania Sweitzer, assistant director of the East Side Sports Medicine Center in New York. "There are no problems, he should do great. If the last few games of last season are any indication, he'll be able to score. . . . I don't have any problems with his knee."

King, 30, returned to the Knicks for the final six games of the 1986-87 season after missing most of that season and all of 1985-86 recuperating from knee surgery. In those six games, he played 214 minutes and averaged 24.5 points per contest, an effort that helped the Bullets decide to sign King to a two-year offer sheet at a guaranteed salary estimated at more than $2 million.

The Celtics also were interested in King but balked at guaranteeing his salary. The team's physician, Dr. Arnold Scheller, would not discuss the specifics of King's case but said the player's knee was tested extensively last week.

According to Scheller, the tests "give you a percentage strength from one side to the other; it doesn't matter what the player says about how he feels, the tests can assess how well he's worked and from there you can analyze how many minutes per game he'd be able to play. The tests are designed to take the guesswork out of it."

In their final analysis, the Celtics decided that the potential risks with King's knee didn't justify a guaranteed contract.

"If it was more likely that he'd only be playing 20 minutes a game and not 40, then there would be less reason to give him any guarantees. They would need contingencies," said a Celtics source. "King would only be augmenting what they had, so the upside wasn't as great and so it wasn't worth the risk. But their not being interested doesn't mean that it was wrong for Washington to be {because their needs are different}. It's a matter of philosophy and maybe neither one's wrong."

Washington tested King one day after his visit to Boston. The Bullets' team physicians would not return phone calls yesterday and General Manager Bob Ferry would only say, "obviously there's a gamble involved."

While conceding that the injury is "the worst kind of injury you can have on a knee," Sweitzer said the gamble isn't as great as some might think.

"When you look at those test results and say how much he can play you're only speculating, you can't prove it," she said. "Bernard has a drive that you can't test -- his knee is sound and it will hold up. People like to compare him to Mitch Kupchak {the former Bullets' and Los Angeles Lakers' forward who had an operation similar to King's and never returned to his previous level of play} and talk about how he was still limping two years after his injury; Bernard's limp was gone after a year."

Sweitzer said that during King's rehabilitation "he worked five to six hours a day for six days a week. Most players would work one to two hours maximum and only three times a week. People don't know how much Bernard went through to get back."

Bullets Notes:

The Bullets requested waivers last night on two free agent rookies. Cut were John Campbell, a 6-10 center from Clemson, and Herb Johnson, a 6-10 center-forward from Tulsa. Forward Jay Murphy, who has missed practice the last two days because of minor back spasms, will not accompany the team tonight for a game in Lafayette, La. against the Utah Jazz. Terry Catledge had a root canal yesterday and also will not make the trip.