After morning practice yesterday, Bullets Coach Gene Shue called Don Collins into a tiny, dim room, shut the door and delivered the bad news: the third-year pro was a Bullet no longer.

Shue waived Collins and put rookie guard Michael Britt on the injured list, reducing the roster to the required 12 players before tonight's season-opener against the Philadelphia 76ers at the Spectrum (7:30 p.m., WDCA-TV-20, WTOP-1500).

When Shue spoke to Collins in the morning, General Manager Bob Ferry was still trying to make a trade for him before the 6 p.m. deadline. There was talk of a deal with the Golden State Warriors, but it never came through. After a half-day's wait, Collins was out of a job.

Collins, who started 21 games for the Bullets last year, came to the team from the Atlanta Hawks in a trade for Wes Matthews in January 1981. Collins averaged 11.8 points a game last season with a season high of 29.

"I didn't expect it at all," Collins said. "I couldn't cut it, I guess. That was the decision that was made. What I think doesn't matter much.

"I don't think I'll be doing anything for a while. It's probably too late to play in Europe. It may be possible to play some CBA (Continental Basketball League) ball. I don't know."

In an interview earlier in the week, Shue said, "Cutting players is very hard. Sometimes you're making a decision that means a guy is either making a couple hundred thousand dollars a year or nothing. You hate doing it."

But Shue said that the team had an abundance of guards, especially with the addition of rookies Jeff Malone and Mike Wilson, and that rookie forward Darren Daye may also play at the guard position periodically.

Britt, who has a sprained left ankle, is eligible to return to the roster after five games. If Shue keeps Britt, he will have to cut another player. That, Shue said, "is a decision for the future, not now."

With the roster logjam cleared, at least temporarily, Shue and the Bullets turn to a much trickier test, tonight's opener against Philadelphia. Before the two teams take the court at the Spectrum, the 76ers will be awarded their championship rings.

Considering how thoroughly Philadelphia dominated the NBA last year, winning all but one playoff game and surging past teams as strong as the Los Angeles Lakers, the glitzy jewelry is an inadequate symbol of the sort of performances demonstrated by league MVP Moses Malone, Julius Erving, Andrew Toney, Bobby Jones and the rest.

The 76ers have everything a team could want: rebounding, scoring, team defense, depth, experience and youth. Philadelphia does not run as many offensive patterns as Washington; it succeeds by isolating its one-on-one players.

The man in the middle makes it work. With Malone, the 76ers have become a team of stars that can play together, a rarity in NBA history. The talk about "the age of Ralph Sampson" is fine, but a little premature with Malone still in his prime.

The 76ers seem gilded with good fortune these days. Even if Erving or Jones should decide to retire, the team has three first-round picks in next year's college draft. Coach Billy Cunningham has even discovered that his sixth-round draft choice, Sedale Threatt of West Virginia Tech, is a spectacular player.

"I don't think they have any real weaknesses," Bullets guard Frank Johnson said. "The only drawback they have is that they don't like to play slowdown, which is what we do."

On the day before traveling to Philadelphia, rookie Jeff Malone tried to shrug off suggestions of edginess by calling his debut "just another game."

But no matter how blase first-year players Malone or Daye may appear, Shue is aware of opening-night jitters, especially against a team as strong and publicized as the 76ers.

"It's not the preseason schedule, that's for sure," Shue said. "But if I didn't think they could play, I'd be nervous as hell. I don't look at Jeff Malone and Darren Daye as ordinary rookies." Malone is the team's third guard and Daye will play often at small forward and, in the future, at off guard.

"We match up as well as anyone against Philadelphia. Of course, they beat everyone, too," Shue said. "But I don't have any worries about them. You have to play them six times a year. I'd just as soon play them right away."

The front-line matchups will be especially interesting to watch. Rick Mahorn will guard Erving, Jeff Ruland will play Malone and Greg Ballard will check Marc Iavaroni.

"I know it sounds crazy, but if we play the way we can, I think the 76ers will be surprised," Shue said.

League officials said that if there is no agreement with striking referees, substitutes from the CBA and college ranks will officiate. A union spokesman said, in that event, the Washington-Philadelphia game will be picketed.