The Washington Bullets, nagged by injuries but showing strength off the bench in recent games, play the Philadelphia 76ers here tonight (8 p.m., WDCA-TV-20).

The Bullets have clinched a playoff berth, but could finish either third or fourth in the Eastern Conference. A Third-place finish would pit them against the sixth-place team in the opening playoff series; and a fourth-place finish would send them agansts the fifth-place team. The Bullets will have home-court advantage in the first round either way.

In the event of a three-way tie between Washington, Cleveland and New York, Cleveland would get third place by virture of having and the best record against the two other teams (5-3), compared to the Bullets' 44 and New York's 3-5).

In the event of a two-team tie, the Bullets would then be the third-place team by virtue of a better-conference record, 25-13, compared with Cleveland's 21-18 and New York's 18-21, prior to last night's games.

A loss by either Cleveland or New York in last night's action would give the Bullets third place.

Meanwhile, so many Bullets are limping that Coach Dick Motta isn't sure who will start against the 76ers.

He doesn't expect forward Bob Dandridge, who is nursing leg and neck miseries, to dress until tomorrow's regular-season finale against the same 76ers in Capital Centre. Dandridge has missed the last two games, both Washington victories.

Tom Henderson, who also has bad ankles, sprained a toe against Boston Thursday night and Motta would like to keep him out the final two games.

Joe Pace, who played well enough against Los Angeles Wednesday night to escape Motta's doghouse, had a sprainged ankle and sat out the Celtics' game. He should be able to play tonight.

Motta's starting lineup probably will be Larry Wright and Kevin Grevey at guard, Wes Unseld at center and Elvin Hayes and Mitch Kupchak at forward. But guards Charles Johnson and Phil Walker, along with forward Greg Ballard, likely will see considerable action, as they did in the romp over Boston.

The Bullet bench was instrumental in both triumphs this week after going inconsistent as the starters.

In January, when the club was atop the Central Division, the reserves were being hailed as the best group in team histoy. But injuries disrupted Motta's substitution pattern and also forced him to start Grevey, then his top backcourt replacement, for the rest of the year in place of Phil Chennier.

Now both Kupchack, who missed a month with a thumb operation, and Wright, who sat out 11 games March with a Sprained wrist, are peaking. Ballard, who is benefitting from more playing time withe Dandrige sidelined, has had back-to-back strong efforts and Johnson, the mid-season emergency free-agent acquisition, has emerged as a Motta favorite.

"I feel better about the bench than I have in a long time," said Motta. "Our late-season injuries have forced me to give some of these people more time and it's helped them.

"Larry has looked loose and free again and that's a good sign. He's been pushing the ball up the floor like he was earlier in the season and he and Mitch are playing together again like before. They give us that spark off the bench and get us running when we have to pick up the tempo."

Wright's 16 points against Boston was his highest output since he first hurt his wrist Feb. 19. The wrist finally had healed enough to allow him to get more range on his jumpshot and more snap on his passes. He had six assists against Boston.

Ballard registered a career high of 16 rebounds agains Boston, scored 15 points and had six assists. He pulled in five offensive rebounds and had 16 points the night before against Los Angeles. He now has reached double figures in points in five out of his last six games.

"He's showing his talents," said Motta. "He's making plays out there that only strong athletes can pull off. He's a smart player and he does little things that make good things happen."

Johnson has averaged 15 points the last five contests and has been usd extensively in tight late-minite situations.

'He's been there before and he knows what it takes to win a playoff," said Motta. "He plays the clock well and he's helping us on defense."

Motta's objective now is to set up a regular playoff substitution pattern, which the players prefer and he likes. But that only will be possible if more injuries don't occur.

"You've got to have everyone healthy in order to set up and kind of regular substitution," said Motta. "Every time we've got into a routine somebody's got hurt. Maybe now we can get things straightened out and back into the groove for the playoffs."