Unless the Boston Celtics suffer an equally devastating blow, the injury to Philadelphia's Darryl Dawkins probably has prematurely ended the NBA's most intense, exciting and marketable title race.

By losing six of their last eight games, including three in a row, Philadelphia has fallen 2 1/2 games behind the Celtics. Now with Dawkins sidelined until at least mid-March with a double fracture of the fibula (small) bone in his right leg, the 76ers will have to start worrying about holding off the rapidly improving third-place Bullets.

Coach Billy Cunningham acknowledged here last week that his team was in trouble even before Dawkins was hurt in the first quarter of Sunday's nationally televised loss at New Jersey. After a dazzling 14-1 start, the injury-plagued 76ers have won just 12 of 23 games.

"We've hit rock bottom as a team," Cunningham said. "We're not playing with any life or enthusiasm. We're going to have to regroup and start going in the right direction."

The loss of Dawkins means that Caldwell Jones will become the starting center with 6-foot-9 Earl Cureton backing him up. That leaves 34-year-old Steve Mix as the only muscle man on the bench.

"The 76ers need Darryl's physical presence," Atlanta Coach Kevin Loughery said upon hearing the news that the 6-11, 255-pound center was injured. "They just don't have much muscle without him."

"It's obvious we're going to have to do something right away," Cunningham said when asked about replacing Dawkins. "We've got some draft choices (eight first-round picks and seven second-rounders from '82 through '86) so maybe we can make a deal."

Ironically, Dawkins reportedly was on the trading block anyway because this is the last year of his original six-year contract. The team's new owner, Harold Katz, has not been impressed with the big center recently. Now a trade before the Feb. 15 deadline seems unlikely.