The struggling Bullets returned home from a 17-day trip to receive a mixed bag of news about their injured players yesterday. Mitch Kupchak has had the cast removed from his thumb and could return by the end of next week. But Phil Chenier appears to be closer to back surgery after going through yet another test.

Chenier underwent a myelogram, a series of X-rays after an injection of dye in the spinal cord. It confirmed that he had a defective disk in his lower back, but team physician Dr. Stanford Lavine said a final decision about whether to operate would not be made until next week.

Chenier has not played since Jan. 8, when he pulled a hamstring muscle. His chronic back condition flared up two weeks later. He spent 12 days in traction at Sibley Memorial Hospital and has since been trying to exercise, but the back has continued to pain him.

Kupchak first hurt his thumb in a game against Golden State Jan. 18 and further tore ligaments in it two days later against Los Angeles. He underwent surgery Jan. 23 and was supposed to be in a cast for four weeks, but it was removed a week early.

Lavine said there was a remote possibility Kupchak could played next week but he more likely would be ready in two weeks.

Kupchak said yesterday that he wasn't about to rush back before he felt confident the thumb, which is now in a brace, would hold up under game conditions.

"My wrist is really weak and my hand is weak and I hardly can move the thumb at all," he said 'I can't bend the thumb or make a fist. But I am encourage that I am about a week ahead of schedule. I'm soaking it every day in warm water and trying to move it.

"I'm scared about it now.I can see the cut and I can't move it and I don't have much confidence in it, but I guess that's normal. It takes time for the ligaments to loosen up.

"I'll play as soon as I can but if Dr. Lavine tells me that I'm risking hurting it again by going out too soon, i won't play."

Kupchak said he had been staying in shape by running and playing in some pickup games. "I just use my left hand," he said. "The scouting report on me is. "Can't go right, play him left. I eat and write left-handed. I even have to start the car left-handed.

"But just having the cast off is a big boost psychologically. The thumb looks almost normal, and that helps. But I'm not ready to try to catch a ball with it."

Without Kupchak and Chenier in the linequp, the Bullets have won only three of 11 games, returning from this last road swing with a 1-6 record since Jan. 13, when they beat Portland to take a 1 1/2-game lead in the NBA Central Division, they have a 3-11 mark that has dropped their season record to 27-26. They now trail San Antonio by 6 1/2 games.

Coach Dick Motta is convinced that the club will benefit from a favorable schedule over the last third of the season. Starting with tonight's game against Buffalo at Capital Centre, the Bullets play 18 of their last 29 contests at home.

However, he acknowledges that first he has to start getting more consistent play from his guards. Other than Kevin Grevey, they slumped horribly during the road trip and have not been able to compensate for the loss of Chenier's 14-point average.

Larry Wright, the usually effervescent jitterbug, especially is going through a difficult period. After averaging 10 points and 32 minutes in the last five games before the trip, he scored only 34 points and averaged only 14 minutes during the seven-game swing. In the last two contests, he played a total of 19 minutes and scored four points.

Although Wright says he will be okay, team sources say he is puzzled over his role on the club and how Motta is employing him in games. Recently, Motta has been using newcomer Charles Johnson more extensively than Wright.

Wright is convinced he can play in the NBA and uses his 43-point effort against Indiana earlier in the year as proof. But Motta now is asking Wright to serve more as a playmaker, backing up Tom Henderson, and he feels his second-year guard is struggling to adjust.

'We are urging him to use his speed and help create the quick temp that is best for him," said Motta. "He's just having a tough time getting the offense going the last few games. We're trying to stress to him to penetrate more so he can dish off. Most of his drives are around the perimeter.

"Teams are trying to get him into a slower game and that's not good for him. And maybe having Charlie on the scene hurt him psychologically because they are the same size. But it shouldn't. We want Charlie to mainly back up Grevey.

"Larry handled the ball when he was in the backcourt with Dave Bing last year and I have confidence in him that he can do it this year. He's going to break out of this in a big way pretty soon."

Grevey averaged 15 points during the road trip but Wright, Henderson and Johnson combined for only 20 more points a game. When Chenier was healthy, the Bullet guards were contribbuting 48 points a game.

"I've got to give them more offense," said Henderson. "I'm not scoring enough. But it's something I think I can change."