Mentally let down by the unexplained absence of their floor leader and physically drained by an overtime loss the previous night, the Bullets were ill-equipped to take advantage of a rare off-night by the Philadelphia 76ers.

Operating without playmaker John Lucas, who was absent here without an excuse for the second time this season, and playing the last seven minutes without Kevin Grevey, the Bullets faded in the stretch and were beaten tonight, 102-93.

Grevey reinjured his sore right index finger when he was hit by another player's elbow, and he went to the dressing room with the Bullets trailing, 83-74. He said afterward that he hopes to play in Friday night's home game against San Diego.

Jeff Ruland was the only Bullet effective on offense. The rookie from Iona led the scoring with 17 points and had a season-high 20 rebounds in 38 minutes.

"We had a real good chance to win this one," Coach Gene Shue said. "We were within five points (85-80) with five minutes to play and had them playing at our tempo.

"We just couldn't keep it up," the coach continued. "I think we were physically spent after that loss to Boston. We probably had a mental letdown, too."

When Lucas missed the bus trip here and the players wondered all afternoon where their floor leader was, it had a very unsettling effect on the team, Grevey said.

"The uncertainty of what was going to happen to John had to bother us," Grevey said. "We need John to win. He's really effective in the running game. There's no doubt, we need Luke."

Frank Johnson started in Lucas' place, just as he did here Jan. 6 when Lucas was first absent for a game with the 76ers.

"Up until game time I thought he was coming," Johnson said. "But I was preparing myself. I've got to learn to control the tempo of the team and not let it get out of hand. I thought we were doing that tonight until the end, when they got all those quick baskets."

Johnson failed to score in the first half and wound up making five of 12, for 12 points. He had 11 assists.

Philadelphia, loser of an emotional game at Milwaukee the previous night, appeared an easy target for an upset. They were lethargic, and there were only 8,163 fans at the Spectrum, where the 76ers rarely have had any trouble running past the Bullets.

After building a 20-10 lead midway through the first quarter, the 76ers let down when Coach Billy Cunningham went to his reserves.

Despite making only six of 19 shots (32 percent), the 76ers managed to stay between five and nine points ahead of the struggling Bullets in the second quarter. They took a 44-36 lead at intermission.

With Bobby Jones scoring 10 of his game-high 22 points in the first 6 1/2 minutes of the third period, Philadelphia built its biggest lead, 64-48, before letting down again.

The Bullets, who have lost five straight to the 76ers, came back with 10 straight points, the first five by Ruland. Cunningham called timeout to regroup, and the team increased its lead to 70-60 before Garry Witts, teaming with Johnson in an all-rookie back court, made a three-point play to bring the Bullets within seven going into the final period.

The Bullets made only one of their first six shots in the fourth quarter and fell behind, 81-67, before their last futile charge brought them within five, 85-80, with 5:20 remaining. At that point, Cunningham put Julius Erving (18 points) and Maurice Cheeks back in the game, and the 76ers pulled away despite two three-point shots by Johnson and one by Don Collins.

In Boston, Kevin McHale scored 25 points as the Celtics survived a late rally by Atlanta and won their 13th straight, 113-109.

In other games, Kiki Vandeweghe scored eight points in overtime to give the visiting Denver Nuggets a 135-133 victory over the Phoenix Suns; Foots Walker's two foul shots with five seconds left helped host New Jersey beat the San Antonio Spurs, 93-90; in Dallas, Ricky Sobers scored 14 points in the fourth quarter as the Chicago Bulls beat the Mavericks, 102-92; in Oakland, the Kansas City Kings used an occasional illegal zone defense to beat the Warriors, 117-116.

In Richfield, Ohio, Ron Brewer scored 11 of his 31 points in overtime as the Cleveland Cavaliers defeated the San Diego Clippers, 113-107; and Kareem Abdul-Jabbar's 28 points led the Los Angeles Lakers past the host Jazz, 120-112.