Bill Walton's request to be traded by the Portland Trail Blazers is nothing new in professional sports.

But his reason for asking is new. And it is important.

Usually a guy wants to be traded because it snows too much in Buffalo.

Or the owner won't give him a yacht for every home run he hits.

These guys in their 20s who are being paid tall piles of money to play children's games and they go around crying so much you'd think the whole sports would had a bad case of diaper rash.

Bill Walton isn't crying.

He is angry.

Unless the best evidence we have is wrong, Walton has good reason to be angry.

Though Walton isn't talking to the press and his advisers/spokesmen, Jack Scott and John Bassett, have not answered the question directly, it seems Walton has asked to be traded because the trail Blazers asked him to play last season when he was hurt.

More than that, they asked him to play after taking a pain-killing drug.

Injections of pain killers are common in serious sports competition, from the high school level upward. Most often, doctors explain the injections by saying no further unjury is risked. They say the injection will only prevent pain and allow the player to do what he wants - compete. If the injury is so serious that further competition might result in greater damage, then no injection is given.

That's what the doctors will tell you.

What they do can be different.

I once watched a doctor give a foot-ball player an injection during the first quarter of a game. The player had hurt a knee. He was an important part of the team, an all-star linebacker. He begged to go back into the game.

The doctor put the linebacker on a training table and probed the knee with his fingers. Then he injected the knee with Xylocaine, a pain-killing drug. The linebacker rushed back to the sidelines, trotted back and forth a while and then went into the game.

On the first play, he collapsed.

They carried him off the field this time.

He had surgery three weeks later.

He never played football again.

I wrote a detailed story about the incident and the doctor, a longtime friend of mine, had one comment. "I hope I don't get sued for that," he said.

Walton has never liked the practice of pain-killing injections. In Jack Scott's new book, "Bill Walton: On the Road with the Portland Trail Blazers," a recurring theme is Walton's abhorrence of the you-will-play-with-pain-by-getting-a-shot philosophy. Walton preferred a natural-herb ointment normally used on horses' legs.Throughout the book, Scott and Walton praise the Trail Blazers' trainer and doctor for not pressuring Walton to accept the pain killers that Scott calls "institutionalized violence."

Portland won 50 of its first 60 games last season and seemed certain to win another NBA championship. Then Walton hurt both feet. Without the 6-foot-11 center who is the league's most valuable player, Portland won only eight of its last 22 regular-season games.

At UCLA and with the Trail Blazers, Walton has been a team player beyond compare, selfless and sharing. With the playoffs starting last season, it seems possible that Walton, to help his team and teammates when they needed it most, would yield to pressure and accept a pain-killing drug - if the doctors assured him the injection couldn't make things worse.

In the second game of the playoffs, Walton broke his left foot. Some people believe it was broken whne he was convinced to accept the injection. Doctors wouldn't say that.

Another Trail Blazer player, reserve cente Tom Owens, said yesterday he didn't know why Walton would want to be traded.

"The only reason I could think of . . . is the way the medical situation was handled in the playoffs last year," Owens said. "I think Bill was unhappy about the way it was handled, maybe something about playing on the injured foot."

The foot still hasn't healed. Walton is on crutches yet and Scott says he won't be ready to play when training camps open.

Chance may have played a role in this affair.

If we accept Scott's report of yesterday - he said of Walton. "I have never seen him so upset and angry" - we need ask why a man so upset and angry took four months after the playoffs to demand a trade.

Perhaps because that's when an alternative was created. Walton's hometown of San Diego became an NBA city, taking in the on-the-lam Buffalo Braves. Walton says San Diego is one of seven NBA teams he's play for.

We also need ask why the Trail Blazers gave in to Walton so easily. They are losing the NBA's best player when he is legally bound to them for two more years.

Maybe they talked about Xylocaine.

And maybe they remembered reading P.159 of Scott's book.

That's the page where Scott writes about players getting shot up before a game.

Scott writes about lawsuits on that page, saying, "Houston Ridge, a former San Diego Charger, won an out-of-court settlement of well over $100,000 after he filed suit against the Chargers, claiming he was injected with pain-killing drugs so he could play on a broken leg . . ."