That decision will almost certainly mean star witness Jose Canseco will not answer questions during hearings that are officially called, "evaluating Major League Baseball's efforts to eradicate steroid use."
In a recently published book, Canseco accused various players of using steroids.
Commissioner Bud Selig has announced he will testify as well.
Because he was not granted immunity, Canseco is expected to invoke his fifth amendment rights and refuse to answer questions.
"Those could expose him to criminal liability and we're just not going to risk that," said Robert Saunooke, Canseco's lawyer.