One Tulane basketball player and one student pleaded guilty yesterday to charges of conspiring to shave points in the gambling case that has shocked the private university in New Orleans.

In a brief, unscheduled appearance before District Judge Alvin Oser in New Orleans, guard Bobby Thompson pleaded guilty to one count of conspiracy to commit sports bribery and student David Rothenberg of Wilton, Conn., pleaded guilty to two counts of conspiracy and one count of possession of cocaine.

They will be sentenced July 9 after the Department of Corrections completes a sentencing investigation, a spokesman for Oser said.

Thompson was indicted on two counts of conspiracy to commit sports bribery, but attorney Russell Schonekas had said he would attempt to plea bargain to reduce the charges to one count. Thompson, a reserve guard, has been cooperating in the investigation into alleged point shaving in three Tulane basketball games in February, and has admitted to distributing money in connection with the alleged scheme.

Of the eight people indicted in the case, Thompson and Rothenberg had been charged with the fewest counts. The penalty for conspiracy is 2 1/2 years in prison and a $2,500 fine. The maximum penalty for possession is five years and $5,000.

Two other players, two more students and two nonstudents were also charged. Center John (Hot Rod) Williams and guard David Dominique are charged with three counts of conspiracy and two counts of sports bribery.

Two more players, forwards Clyde Eads and Jon Johnson, were given immunity from state prosecution by Orleans Parish District Attorney Harry Connick for their testimony before a grand jury last week.

In another move yesterday, Oser ordered Tulane to protect game films and documents of the past four basketball seasons, and will decide Monday whether the school will be ordered to turn them over to attorneys for Williams and Dominique, who hope to use them to show their clients' innocence.

Dominique's attorney, Edward Castaing, contended the records could be vital to the defense of Dominique and Williams. He said they may show that Williams and Dominique did nothing wrong, while reflecting badly on the performances of Eads and Johnson.

"The tapes and statistics are essential to the defense," Castaing said. "I think it will show that both of them played 100 percent. I intend to compare the play of Dominique and Williams to the play of the two admitted point shavers. I think it will show a contrast."

Statistics in the Memphis State game show that Eads, Tulane's main outside shooter, took just one shot in the contest. He also had five turnovers. Afterward, he said he had an injured wrist.

Williams scored 14 points and had five rebounds. The star center averaged 17.8 points and 7.8 rebounds for the season.

Against Southern Mississippi, Williams had 15 points and six rebounds. Dominique, a sophomore, had four points and three assists against Southern Mississippi, and 10 points and six assists against Memphis State.

All three opposing coaches have said they saw no evidence of point shaving.

"We remember the game very well," said Southern Mississippi Coach M.K. Turk. "We thought it was one of the better played road games we had all year. We thought there was a lot of intensity. Williams played a particularly good game. Our defense was geared to stop just him, and he still scored. He had 11 points in the second half."

Virginia Tech Coach Charles Moir said he was astonished by the allegations of point shaving against his team.

"I was shocked that they even mentioned that game," Moir said. "As soon as that came out, I went back and reviewed films of both of our games. We had a nine-point lead at halftime and they still came back. I couldn't detect anything at all."

Also yesterday, a team of lawyers working for Williams threatened to ask for a gag order against the district attorney's office. Attorneys Michael Green of Chicago and Joel Loeffelholz and Alan Tusa of New Orleans are angered by "leaks" leading to reports in which details of secret grand jury testimony and statements to the district attorney have been revealed.

Green also has said that the case against Williams is based on testimony by "drug addicts." Connick has said he believes cocaine was a motivating factor in the case, and may have been used to bring the principals together.