It hasn't been the happiest of seasons for Bullet guard Tom Henderson. He's been nagged by ankle injuries and criticized for his defense. He nearly lost his starting job in playoff series against Philadelphia.

But even those problems are overshadowed now by the task that he and his guard mates face entering the NBA championship round against Seattle.

The guards are well aware that they probably hold the key to the Bullets' chances. If they can control the SuperSonics' high-powered backwurt, they feel the Bullets can win the title. But if Fred Brown, Gus Williams and Dennis Johnson are allowed to score at will. The balance of power could shift to Seattle.

These are the same Bullet guards who had trouble stopping almost any opponent late in the regular season.Their defense has improved considerably in the playoffs, but Henderson hasn't forgotten the past.

"All I read and heard is that I couldn't play defense," he said. "I know that isn't true but now everyone believes it. People forger this is a team game. No one guy can stop anyone by himself. You need help and that's what we've been getting in the playoffs."

Henderson played a major part in wrapping up series victories over San Antonio and Philadelphia with sparking defensive efforts in the decisive sixth games of both rounds.

Against the Spurs, he guarded George Gervin for the first time in the series and helped limit him to a playoff low of 23 points. And he took over the defensive assignment in the second half against Philly's Doug Collins and held him to four points, 25 fewer than he scored in the first half.

"Sure, I got a lot of satisfaction from those two games," he said. "I think they showed what I can do on defense. They both are great players and when you can do a job against them, your have to feel good about it."

Now h will be asked to control Williams, the sparkplug offseason free-agent acquisition who directs the Sonics' attack. Other matchups will have Kevin Grevey on Dennis Johnson and either Larry Wright or Charles Johnson on Brown, who came off the bench to average 16 points during the Western Conference final series against Denver.

Both Dennis Johnson and Williams topped Brown's figures in that round. Williams led tha Sonics with 20.7 and Johnson was second with 18.3.

"Gus will present a problem for me because he handles the ball so much," said Henderson. "He's got it 90 percent of the time. I'll have to stay on him and make him work so he'll get tired.

"He can really shoot when he gets going. My goal will be to keep him below his season average (18 a game). I'll make sure he knows I'm there every game. I'll bump him and pressure him because I think that will bother him.

"In the regular season, they (the referees) don't let you be quite so physical but it's different in the playoffs. Everyone is more intense and you got at each other harder."

How well Henderson does against Williams could determine his future with the Bullets, even if they win the title. He views his reduced playing time against Philadelphia as a possible sign of things to come.

"Do I think I'll he traded? Well, ever since I got traded by Atlanta (last year) I haven't unpacked my bag," he said. "This is a cold business and you have to always keep that in mind. I just have to play my best and what happens, happens."

Henderson had entered the season with glowing expectations. Coach Dick Motta said he was depending on him to give the team on-the-court leadership from his playmaking spot, a role the former Hawaii star relished.

But a combination of ankle sprains - "They still hurt pretty bad some mornings" - and concern by the coaching staff over his defense gradually reduced his part. Things hit rock bottom in the Philadelphia series.

"I thought I really contributed to our win over San Antonio," he said "but I didn't feel that much a part of Philadelphia. I did something in maybe three games. The other three, not much."

With Wright picking up many of his minutes.Henderson sat on the bench and, as he puts it now, "got really dicouraged.

"I really didn't understand why I wasn't playing. We hadn't talked about it. It was a lack of communication at the time. But it wasn't my job to complain, it was my job to play when I could.

"That's why I decided to go into that sixth game and forget about what had happened before. In the fifth game, I was down and it hurt how I played.

"No one really has ever told me why I lost minutes. I learned by reading it in the papers. I would just like people to tell me what I supposed to do. If we are supposed to be together, we should have better rapport."

Henderson said he viewed the Philadelphia episode "as someone saying to me, 'Welcome to the NBA - again.' I was just glad that our bench responded well and made up for what I didn't do."

"If we had lost, things might have been different. But when we were winning, I kept my mouth shut. Why burden the team with my problems at that point? But even they kept coming to me and asking, 'Are you hurt?'"

According to Motta, Henderson, who is shooting only 40 percent in the playoffs, had his playing time reduced in favor of Wright because "Larry is more of an offensive threat and that helped keep Philly's guards honest on defense."

But Henderson says people "have the wrong idea about my offense. In Atlanta, they'd clear out a side for me and I could work one on one. Here, they don't have even one play for me. Iknow I can score if I have a chance."

Williams has found out this season what an offensive-minded Henderson can do. In four games against Seattle, Henderson has averaged 17 points, six more than his regular-season total.

"He likes to go against Gus," said Motta. "That impresses me. And something else does, too. I know the Philly series was hard for Tommy, but you know who was up and cheering for his teammates the hardest? Henderson.

"That showed me something. He could have sulked but he didn't. Those ankle injuries have killed him all season but he never complains. You want something good to happen to a guy like that."

The Bullets worked on Seattle plays most of yesterday's practice. Motta has yelled little in workout this week, a sign he is pleased. Following practice today, the club will fly to Seattle and work out there Saturday . . . Motta, who lost most of his voice doing postgame interviews after Philadelphia series, is improving daily . . . The Bullets have available T-shirts displaying Motta's Philly slogan, "The Opera Isn't Over 'til the Fat Lady Sings."