Two weeks ago, I watched the Southeastern Conference basketball tournament on television. It was played in Birminham, Ala., and the game that particularly caught my attention was between Kentucky and LSU.

Judging by that contest, college basketball is healthy. The game was exciting, the teams played hard and the fans yelled and screamed.

And no one seemed to care that at one stage of the game cight of the 10 players on the floor were black. The black cat has been let out of the bag, it seems. So many black cats have been let out that in pro basketball, some owners and general managers don't like it. The Feb. 26 issue of Sports Illustrated magazine says there is an "ill wind blowing" in the National Basketball Association. One owner says the decline is partly because 75 percent of the NBA is black while 75 percent of the fans are white.

Other reasons given for lowered attendance figures include too long a scheduled and regionalization of NBA games on television. But, S. I. continued, a top executive from one of the NBA's oldest teams said the gravest problem might be that "the teams are too black." In other words, probasketball is now viewed as a "black sport" by too many people -- white people, that is.

I don't care to comment on these statements about the condition of the NBA, or whether these feelings and attitudes are correct. What matters to me is the statement it makes about American society and what America does about it.

Amateur and professional sports in the United States are open to all. And the black community is very aware of this. Why else would blacks devote so much energy to sport? The American dream is to make of yourself what you will, to reach for the sky, fulfill your potential. Accustomed to facing discrimination again and again in other endeavors, black people felt it was nice ot finally find something like sports, where only the results mattered.

Little do those eight black players on the LSU and Kentucky teams realize what possibly lies ahead. They were trying to impress all those NBA scouts. Meanwhile, most NBA owners are trying to impress their white, middle-class fans.

Dealing with discrimination in private life is nothing new to black communities. Getting into the best schools, getting a good job, trying to advance, making our presence felt, trying to contribute to society are perennial problems. We cope somehow.

But I guess our big mistake is that we thought out fellow citizens liked seeing us "do our thing" on the courts and fields across the U.S. We spent a lot of time perfecting our "moves." Sports, after all, is entertainment. If you make over $15,000 per year we figure that you allot so much of your income for entertainment: going to see the Bullets or Redskins play means that's $10 the Kennedy Center won't get that week.

So, to our disappointment, in what we thought finally was an open, public and freely competitive discipline, we now face new parameters of acceptability. The comments by NBA executives are disturbing: Are we to expect rigid quotas in pro sports in the '80s?

Some people say there already are quotas on pro teams. Should we black athletes now assume that teams have to be either 100 percent black and strictly entertainment, like the Harlem Globetrotters, or less than 45 percent black like baseball, football and hockey, so as not to arouse the subliminal ire of white America?

I'd like to know.

I often wonder why I was so "acceptable" when I was coming up. Was it because I didn't wear red whoes and purple shirts or walk around with a comb stuck in my hair? No. It was primarily because I wasn't a threat to tennis or its values.

How could I be a threat? I was only one player, and there didn't seem to be any more black players lined up behind me. If you think some tennis players today are vulgar, unsports-manlike or crass, honestly now, how much more would you be turned off if those players were black?

Don't think pro basketball wasn't warned or that baseball and football aren't now keeping tabs on the seemingly positive correlation between the "blackening" of a sport and the lowering of attendance figures. One glaring example comes to mind. It happened 10 years ago in South Bend, Ind., in the field house of the most famous highly spirited, religiously-affiliated university in the world -- Notre Dame.

Johnny Dee was coaching the highly rated Irish against Michigan State. At one point, he put in five black players on the court -- Austin Catt, Collis Jones, Sid Catlett, Bob Whitmore and Dwight Murphy. They were booed.

Dee, interviewed by telephone yesterday, said he felt the boos were aimed at him for inserting Whitmore, who was not playing well that day, in place of Boddyd Arnzen, a popular player and the team captain. It also has to be said that the Irish fans were watching their team give a subpar performance. They lost, 71-59.

But the five blacks took the booing personally and refused to play again for Notre Dame until they received a written apology from the school.

They got it.

Are incidents like that passe? I hope so. But if the "too-black" NBA can't amiably resolve its racial questions, there could be serious problems ahead.

In my 25 years of playing tennis. I have signed more autographs for white kids than black kids. But it now appears that when they become old enough to Conomically choose between the Kennedy Center or the Capital Centre, they may opt for the performing arts or stay home.

If it ever comes to the point that yesterday's kids avoid the Bullets because they're too black, then God help us all.