The two injuries are considered minor in nature, but they are enough to make Coach Dick Motta shudder. Motta needs only to think back to less than a year ago when other supposedly harmless ailments began two nightmarish months for the Bullets.

Both Elvin Hayes (sore neck) and Kevin Grevey (sore knees) missed practice yesterday. They are expected to play tonight at 8:05 against Cleveland in Capital Centre. But Motta wonders if this is the start of an unwelcome trend.

Last year at this time, more than one-fourth through the regular season, Washington had a 15-9 record and was in the midst of its best basketball of the campaign. Now the Bullets are 16-8 and probably cannot play much better than they did during some junctures of their just-snapped nine-game winning streak.

"Things were going so well for us last year early, too," said Motta, who still is hobbing from his week-old knee operation. "All people remember is the injuries. I look at what we are doing now, how well we are playing and how much people respect us and then I remember what happened to us last year and I hold back a little."

Hayes twisted a muscle in his neck in the opening minutes of Saturday night's loss to Kansas City. He said it was quite painful then, but was much improved after treatments. Grevey has had problems with his knees since the start of the season and has had fluid drained from both.

"When you are playing like we are," said Motta, "you don't want anything to disrupt it.We are moving our bodies well and there is a good sharpness about our play."

But the team's continuity, as it found out last season, can be quite fragile despite great depth. If a Hayes or a Bob Dandridge or a Grevey misses some games, Motta's substitution pattern is disturbed and the Bullets' sometimes slight talent edge over many of the league's other clubs is reduced considerably.

The Bullets and Motta would of course, like to play through an entirely healthy season, if for no other reason than to find out how good they really could be through a regular schedule. They know last season's 43-39 record was no reflection of their ability; the way they are playing now, they feel 55 wins is not an undeasonable goal, but only if injuries don't ruin them again.

Meanwhile, the NBA, still not satisfied with its three-man officiating crew setup, will do some more experimenting, beginning tonight, using an idea long advocated by the Bullet coach.

Instead of the lead official staying in the same area the entire game (along the out-of-bounds line in front of the team benches), he now will become part of a three-man rotation during games. Each official will get a chance to make calls underneath the basket, out in front of the basket and along the out-of-bounds line. And instead of running in front of the benches, they will be positioned along the opposite side, as they were when the season began.

"We just felt that we wanted to experiment with a rotation setup and see how it worked," said Norm Drucker, head of NBA officials. "A lot of coaches (including Motta) felt that the most experienced official wasn't being involved enough in calling shooting fouls. They think rotating utilizes the senior guy better."

Some Bullet officials also have maintained that the new rules cracking down on hand-checking were instituted in part because of Washington's NBA title. Drucker conceded that the final-round playoff between Washington and Seattle probably was the final evidence the league needed to make changes.

"We got a very bad viewer response about all the hand-checking and holding that was going on in that series," he said. "A guy like Wes Unseld was doing it all the time and some people felt it just wasn't good basketball.

"We don't want to eliminate contact completely. Then it wouldn't be our game anymore. So people still can use their body against someone else. I'll tell you, I've been watching Wes lately and he's adapted to the new rules beautifully. After all these years in the league, when he was all hands and knees, you might think he'd have trouble, but he's learned to live with the change."