Julius Erving just wants to know, one way or the other. Coach Billy Cunningham feels the same way.

Just tell us, Darryl Dawkins, are you up to playing against the Boston Celtics or not in Wednesday night's second game of the NBA Eastern Conference final?

The Philadelphia 76ers' 6-foot-11 center took himself out of Sunday's humiliating 121-81 loss at halftime. He said later his right leg had been hurting. X-rays yesterday revealed no new injury and team physician Michael Clancey said the double fracture of the fibula incurred Jan. 17 was healed. The 76ers' practice was closed, but a team spokesman said Dawkins worked out.

After Dawkins was hurt Jan. 17, he missed 28 games before returning to action March 24. He has complained that his leg still bothers him, but on occasions--such as the opening game of the miniseries with Atlanta, when he scored 27 points and blocked eight shots--he has showed no signs of the injury.

"Sometimes it feels decent, but it never feels great," he said Sunday. "I'm still getting heat and ice treatments and I don't know what else to do. I hope I'll be able to help Wednesday."

Erving and several other teammates appear to have tired of Dawkins' complaining. This is the time of year when injuries, when possible, are forgotten.

"What we need is a definite yes or a definite no, so we can plan accordingly," Erving said. "I know it would be a relief to all of us. It certainly would make Billy's job easier if he knew what to expect."

The bulky Dawkins is essential if the 76ers are going to match up with the Celtics' big men. But if he can't get more than the two rebounds he got Sunday, his value is question-able.

"I don't know if Dawkins helps that much or not," Bullets Coach Gene Shue said yesterday after watching Sunday's game on television. "He can't guard (Robert) Parish and he's not rebounding. Philadelphia is more effective when they have their quick lineup in because their defense sets up a lot of easy baskets."

When Dawkins is on the bench, Cunningham usually goes with Erving and Bobby Jones at forward and Caldwell Jones in the middle. Both Joneses are strong candidates for the league's all-defensive team, and Erving sets up a lot of transition baskets with blocked shots and steals.

"If Darryl is unable to play, we'll just have to go back to doing what we did when he was out," Erving said. The 76ers won 21 of the 28 games Dawkins missed.

With or without Dawkins, it is difficult for many to comprehend how a team that won 57 games during the regular season and six in the playoffs against Atlanta and Milwaukee could look as inept as it did Sunday against Boston.

There are several reasons.

* The well-rested, emotionally ready Celtics played an exceptional game and dominated the rebounding, 67-50.

* The weary 76ers, who finished a physically demanding six-game series with the Bucks in Milwaukee Friday night, have to run to be effective. If a team can't rebound, it can't run, and with Caldwell Jones playing only 12 minutes before fouling out and Dawkins hurting, there wasn't enough size to handle the Celtics.

* Erving and Andrew Toney are Philadelphia's only offensive strengths when the 76ers have to run plays, and neither was effective. Toney had four points and Erving was scoreless in the second half.

"It will be a completely different format Wednesday," Boston Coach Bill Fitch said. "We'd like to play the same way again, but things just don't work that way. They'll make adjustments. I anticipate a tough game every time we play Philly."