About the only good thing that's happened to the Boston Celtics in the last three days is the news that Red Auerbach has decided to return next season as general manager.

The Celtics, a team with the third-best regular-season record, are in trouble, down 2-0 to the Milwaukee Bucks and on the verge of being eliminated from the playoffs in the second round.

The Bucks held the Celtics to nine points in the fourth quarter as they made up a 17-point second-half deficit and stunned Boston, 95-91, Friday night at Boston Garden in their best-of-seven Eastern Conference semifinal playoff series.

The Celtics played without all-star forward Larry Bird, who had the flu. Bird is expected to play in Game 3 Sunday in Milwaukee (WDVM-TV-9 at 1 p.m.).

The Celtics played poorly in the first game of the series, a 116-95 loss Wednesday. Coach Bill Fitch said his team quit, but Friday, even without Bird, the Celtics looked more determined. They took a 15-point halftime lead as Danny Ainge made 11 of 12 shots and Scott Wedman went six for six.

The Bucks wore them down after intermission, however. Ainge made only one of 10 shots in the second half and Milwaukee methodically worked itself back into the game.

"We're in trouble now, big trouble," said Fitch. "If we get Larry back, that'll help, but we still have troubles."

Fitch used Ainge until he almost dropped Friday and veteran Tiny Archibald played only 19 minutes. Fitch said he wouldn't change his substitution pattern in Game 3 and said nothing is wrong with the team that they can't correct.

"We've got to really pick ourselves up now, though," he said. "This is probably a tougher situation than when we were down 3-1 to Philadelphia two years ago."

The Celtics obviously missed Bird, particularly his leadership. They missed 13 of their last 14 shots Friday and had no one to turn to at the pivotal point in the game. The offense was helter-skelter while the Bucks got the ball to players who delivered--Sidney Moncrief (20 points), Junior Bridgeman (19) and Marques Johnson (19).

Bob Lanier has also outplayed Robert Parish in the series. Parish has scored 32 points and collected 22 rebounds in 69 minutes. Lanier has scored 34 points with 17 rebounds in only 54 minutes.

Because of bad knees, Lanier hasn't played in back-to-back games all season, but Coach Don Nelson said he will use his big center both Sunday and in Monday night's fourth game.

In the Western Conference, the San Antonio Spurs, who look like the best team in the playoffs so far, and the Los Angeles Lakers, are already only one game away from sweeping their conference semifinal series.

The Spurs went up 3-0 in Denver Friday with a 127-126 overtime victory over the Nuggets.

The hero for the Spurs hasn't been George Gervin or Artis Gilmore, but 6-foot-1 point guard Johnny Moore. He scored a career-high 39 points Friday, including all nine in San Antonio's overtime production. Moore also had 12 assists and, in the three games, is averaging 29.7 points and 16.3 assists.

San Antonio will try to end the semifinal series Monday night in Denver.

In Portland Friday, the Lakers also needed an overtime to take a 3-0 lead over the Trail Blazers.

Kareem Abdul-Jabbar was the difference in the extra period as he made two sky hooks, one a 16-footer, and five straight free throws. He finished with 30 points, eight rebounds and four assists.

The most surprising thing in this series isn't that the Lakers are winning, but how they're winning. With Bob McAdoo and James Worthy out with injuries, Coach Pat Riley is using only seven players--his starters and Mark Landsberger and Michael Cooper. The Lakers are still running and depending on the fast break for much of their offense. That series resumes Sunday in Portland.

The Knicks and 76ers also will play the fourth game of their series Sunday at Madison Square Garden (WDVM TV-9 at 3:30).

No team in NBA history has come back from a 3-0 deficit to win a best-of-seven playoff series and only five teams have come back to win after being behind 2-0.