Undated (AP) _ The days when the United States could win an international basketball game simply by walking on the court are over and John Thompson is determined to leave nothing to chance at the Seoul Olympics, even if it means angering a few people.

Thompson, the Georgetown coach who will direct the U.S. Olympic basketball team, is known for sheltering his players from the public and the trials that begin Wednesday in Colorado Springs will be no different.

They will be closed to all except Thompson's staff, officials of the Amateur Basketball Association of the United States, NBA scouts and representatives of sneaker companies.

The United States Basketball Writers Association has protested the exclusion of the media from the practices and several news organizations have threatened to go to court to gain entrance to the tryouts.

There is some possibility the closed-door policy may change or be modified, but officials make it clear that winning is the top priority.

''We're still looking at possibilities of the media being allowed into the sessions but we don't consider this a media event,'' said Big East Commissioner Dave Gavitt, the chairman of the Games Committee.

Ninety-three players received invitations to try out for U.S. team and as of Thursday, 85 intended to be one of the 12 to wear the uniform with ''USA'' across the chest. The impressive list included the first team of the AP All- America team and most anyone else that made a post-season team with an All- in front of it.

Thompson, who will invite about 20 of these players to a summer camp at Georgetown for the final cuts, has a rough road to the gold medal ahead of him. The United States lost the Pan American Games gold medal last August to Brazil. The last time the United States lost the Pan Am gold was 1971 and the next year the United States lost the Olympic gold for the first time.

The Seoul Games will also mark the first Olympic basketball confrontation between the Soviet Union and the United States since 1976. The Soviets are not the only team Thompson has to worry about as Yugoslavia has consistently proved itself worthy as an international opponent.

''There's no doubt the rest of the world is catching up,'' said Gavitt, who will be involved with his fourth Olympic team.

Catching up with the U.S. players will be next to impossible for the media.

''These players are going to be in a 2 1/2 to 3-hour morning practice and a 1 1/2 to 2-hour session in the afternoon,'' Gavitt said in explaining the closed tryouts. ''That's five hours on the court in a addition to an hour for taping and stretching. That's an 8-hour day and I just don't see the time available for these kids to do interviews.''

Thompson will be available each day of the trials via a conference call but the only eyes on the players until a doubleheader scrimmage in Denver's McNichols Arena on May 24 will be of the two representatives from each NBA team and those people from the sneaker companies, who are allowed in according to one ABAUSA official because of a ''sizable donation.''

Eight players have turned down the invitations for a variety of reasons.

Louisville's Pervis Ellison and Jeff lebo of North Carolina cited nagging injuries that need extensive recuperation.

Temple's Tim Perry and Gary Grant of Michigan said they needed the time for academic work to ensure on-time graduation.

Others such as Oklahoma's Harvey Grant and Mookie Blaylock, Ed Davender of Kentucky and Duane Ferrell of Georgia Tech never gave a definitive reason for the refusal.

''We expected some to say no, figuring the number would drop by seven or eight,'' Thompson said. ''I don't think it's an un-American-like activity. But those are the factors we have to deal with.''

Gavitt said he was surprised the number of those declining wasn't higher.

''I thought the number would be higher because usually the Games are held in July or August but this time they will be in September so it will affect school for some players,'' Gavitt said. ''Then September is also the starting time for your NBA camps so some of the seniors had a difficult decision to make.''

The difficult decision of who will be on the team is Thompson's but each selection must be approved the by Selection Committee.

''In '76 and '80 the team was selected by the Player Selection Sub- Committee with the coaches giving daily reports and opinions in meetings,'' said Gavitt who coached the 1980 team that was deprived of a chance at a gold medal because of the U.S.-led boycott of the Moscow Games. ''(1976 Coach) Dean (Smith) and I both got pretty much what we wanted but not totally, but it wasn't something we couldn't live with.

''Before us, Henry Iba had no control over the selection of his team but the United States was always good enough to survive. The process changed for the 1976 team when control went from the AAU. Active coaches and administrators got more involved.''

The process changed again with the 1984 team coached by Bob Knight and Thompson will have the same privilege of selecting his own team.

''The Sub-Committee still is in consulation with the coach and his staff and it still approves each selection as system of checks and balances.''

Gavitt says increased competition makes the selection process more important that ever before.

''That's why it no longer is a matter of picking the 12 best players but rather the 12 best that comprise a team,'' he said. ''Eight or nine players will stand out and then the coach has to look for specialists whether they be defensive, 3-point shooters or ballhandlers. He has to find players for the 9, 10, 11 and 12 spots that will be willing to sacrifice, not play so much and be willing to accept the role of cheerleader.''

One man attending the Trials who shouldn't worry about how much he'll play is David Robinson of Navy, the 1987 College Player of the Year.

Robinson was the first player taken in last year's NBA draft but a Naval commitment has kept his status as an amateur intact and he says he is ready despite being away from competition since the Pan Am Games.

''I'm not going there just to make the team,'' the 7-foot-1 Robinson said of the trials. ''I want to be one of the best players there, to stand out. ... Besides, I don't think John Thompson would be happy if I came out with the attitude of being happy just making the team. ... I expect at least that much from myself.''

End Adv For Weekend Editions May 14-15