Marvin Webster, the "Human Eraser," has learned a lot of lessons in his short National Basketball Association career. The most important one, he said, is that, "This is a business, not something you do just for fun."

Webster has come by his lessons the hard way - through an illness that threatened his career and an unahppy time as backup center in Denver. Now he's about to apply what he's learned to navigate the turbulent waters of free-agentry.

Seattle is a talented young team capable of doing many things and the 7-foot-1 Webster is a major reason why. He is the intimidating center who enables the Sonic defense to gamble, the strong rebounder who get them the ball so they can run and a man with the offensive moves to get them points inside.

He has averaged 16.7 points, 12.8 rebounds, three assists and 2.8 blocked shots in the playoffs, "and that only shows half his worth," said teammate Johnny Johnson. "We're a team and everyone contributes, but Marvin is what makes us great instead of just good."

Webster, who becomes a free agent at season's end, would like to stay in Seattle, but Los Angeles and New York are both reportedly ready to offer him between $500,000 and $700,000 a year for his services.

Seattle owner Sam Schulman, has already gone on record saying that the $800,000 a year Denver has signed David Thompson for "is too much. I don't think anyone is worth that much in the sports arena. We're going to give Marvin a darn good offer. Beyond that, we just can't go into the area of salaries that Denver did with Thompson."

"This is business, remember," Webster said. "We'll see."

Webster wasn't always so sought-after.

He was thrust into the national spotlight as a college junior when he led Morgan State of Baltimore to the NCAA Division II national championship in 1974. Pro scouts found out quickly that he had earned his nickname of the Human Eraser.

The following year, the Atlanta Hawks had two of the first three picks in the college draft and took Thompson and Webster, eventually losing both to Denver of the then American Basketball Association.

Webster's stay in the Rockies was not a happy one.

He had contracted hepatitis prior to his senior year at Morgan State and it flared up again his rockie season with the Nuggets. Webster played only half the season, and was sluggish and basically ineffective when he did play. The word got out that he would never be completely healthy and not many teams showed an interest in him.

Webster was put on a special diet and vitamin program the next year and had his illness controlled, but the Nuggets had already soured on him.

"They panicked at my illness," Webster said. "When I was going well, they wanted me bad, but when I got sick, they changed from night to day. They had a whole new attitude with me."

Even though Webster's diet and vitamins enabled him to play normally all of last year, he was used sparingly behind Dan Issel.

Seattle Coach Lenny Wilkens was an analyst for CBS television then and he happened to see Webster a couple of games when Issel was injured.

"Marvin could do the same things all the other superstar centers could do," Wilkens said. "I thought he was great."

The first move Wilkens made after becoming the Sonics' personnel director was to acquire Webster from the Nuggets.

"I feel real good and I don't have any health problems," Webster said. "I just don't eat a lot of junk and I take those vitamins."

Webster said his rise to the top was simply a matter of having someone like Wilkens believe in him.

"He allowed me to be myself on the court," Webster said. "I wasn't limited to only being allowed to do certain things. He said I could do everything until I showed him I couldn't handle it. There was no undue pressure or anything."

Webster's favorite shot is a short, turnaround jumpe, but he also has a hook toward the basket to go along with his shot-blocking and rebounding skill.

"All players can't play offense, defense and block shots, but I feel I can," Webster said. "I want to be the best all-round center."

Webster's weakness is that he can be muscled around, which is how the Bullets' Wes Unseld is expected to try to handle him. How well Webster stands up to that treatment is a key to the final series.

"It really doesn't matter to me if the game is physical or not," he said. "It's not my game to just go out and beat up on people, but if I have to be that to win, I'll be that way. If the refs aren't going to call the rough stuff, you can't cry. You just have to push back.

"As long as we don't get into a grudge match and let it throw off out game, we can play physical just like they can.

"That's part of the business."