New York ? The players’ union says Major League Baseball may be responsible for leaking the name of the drug for which Rafael Palmeiro tested positive and might file a grievance, the Daily News reported Saturday.

The union will discuss the issue with the commissioner’s office Monday, Gene Orza, chief operating officer of the players’ association, told the newspaper. MLB spokesman Pat Courtney told the News the commissioner’s office was unaware of a possible grievance.

MLB has not specified what drug the test found, but a person with knowledge of the sport’s drug-testing program told the Associated Press on condition of anonymity it was stanozolol.

Union spokesman Greg Bouris called the leak a “very disturbing matter,” but would not comment further in an e-mail to the AP.

The collective bargaining agreement allows only for the name of the player and the date of his suspension to be released by MLB.

Mets pitcher and senior union leader Tom Glavine said this week he thought it “inevitable” a leak would happen in such a case.

“Once a big-name player got caught … there was going to be all kinds of investigation as to find out what he got caught doing,” he said.

“It’s somewhat frightening that what he took was so easily found out,” Glavine added.

Five months ago, Palmeiro testified before a congressional committee that he never used steroids. The Baltimore Orioles first baseman says he doesn’t know why he tested positive.

Palmeiro, only the fourth player in major-league history with 3,000 hits and 500 home runs, received a 10-day suspension.

The players’ union had challenged the positive test in secret proceedings, and the penalty was held in abeyance until an arbitrator decided not to overturn it.