Tonight's National Basketball Association doubleheader at the Capital Centre was supposed to be Albert King's homecoming.

The New Jersey Nets took King and his Maryland teammate Buck Williams in the first round of June's NBA draft, and both players were looking forward to returning to the area as starting forwards on the same team. The Nets play Philadelphia at 6 tonight and the Bullets play the Knicks at 8.

Williams has achieved his goal. He is leading the team in rebounding and is second in scoring after four preseason games. But King's initiation into professional basketball has not gone well. He has undergone a series of medical examinations on his injured right knee, and there have been conflicting reports about whether he has signed a contract (he hasn't). King says he does not want to discuss his problems at the moment.

The only thing certain about King is that he won't be in a Net uniform against the 76ers tonight. In fact, he is not even expected to attend the game.

Nets officials and King and his attorney, Bill Pollak of Washington, agreed not to talk publicly about King's status. However, they did provide enough information to assemble a chronology of King's problems.

Pollak and the Nets had agreed on a guaranteed four-year, $1 million contract for King more than a month ago. Two days before King was to sign the contract and report to the Nets' rookie camp, he injured his right knee while playing basketball at the University of Maryland.

When the Nets were informed of the injury, the contract signing was delayed pending a report on King's condition.

The original diagnosis by Dr. Jack Hugston of Columbus, Ga., one of the country's top orthopedic specialists, was that King had a sprained knee. When it didn't respond to treatment, the Nets' team physicians, Kim Sloan and Alan Levey, suspected King might have some cartilage damage. They suggested that King undergo an arthroscopic examination, a minor surgical procedure to examine the knee. But Pollak wanted another medical opinion before subjecting King to any surgery.

He took King to see Dr. Kenneth DeHaven of Rochester, N.Y., another respected orthopedic specialist. DeHaven also felt King had only a sprained knee and suggested King rehabilitate it without an arthroscopic procedure. The Nets agreed to wait.

"We just want him healthy," said Coach Larry Brown. "We don't want to rush him."

Because he hasn't signed a contract, King can't work out with the team, so he observes practices and goes to a rehabilitation clinic in nearby Paramas, N.J.

He was reexamined by DeHaven Tuesday and given permission to start moving laterally. King worked out on his own Wednesday, and afterward, Pollak said King felt good.

"Albert doesn't want to talk to the press about any of this yet, but he has full range of motion in the knee, there is no swelling in it and he really feels good," Pollak said.

King is scheduled to see DeHaven again Sunday. If the doctor says he is fit, King will be examined by the Nets' doctors. If he passes that examination, final details of his contract will be worked out and he will join the team, Pollak and the Nets said.

Even without King, tonight's games will be a Terrapin alumni showcase.

Williams has been averaging 13 points and 10.3 rebounds per game and shooting 56 percent from the field. The Nets have won three of four exhibition games.

John Lucas will be making his Capital Centre debut as a Bullet, and another former Terp, Ernest Graham, Philadelphia's third-round draft choice, will appear with the 76ers.