Subpoenas to appear before a county grand jury investigating the death of Len Bias have been prepared for University of Maryland basketball coach Lefty Driesell and Maryland players Terry Long and David Gregg, Prince George's State's Attorney Arthur A. Marshall Jr. said yesterday.

Also subpoenaed was Robert Wagner, who coached Bias and Gregg in high school.

Marshall said he was not certain that the four would be called to testify. He said that Driesell and Wagner, if called, would be among the last of more than 70 persons who are expected to go before the grand jury beginning Monday. The prosecutor said he would like to know more about what Driesell and Wagner, who coaches at Northwestern High School in Hyattsville, said to Maryland players in the hours after Bias' death.

Marshall said at this point he doesn't plan to call Long or Gregg but had subpoenas prepared for them in case he changes his mind. Alan J. Goldstein, a lawyer for both Long and Gregg, said he had told Marshall that he would pick up the subpoenas this week.

Marshall launched the grand jury investigation immediately after Bias' death from what the chief state medical examiner concluded was "cocaine intoxication" from an unusually pure form of the drug. Bias collapsed in his dormitory room on the College Park campus early on June 19.

Long, Gregg and Brian Tribble, a friend of Bias' and a former University of Maryland student, were with Bias when he collapsed, police investigators have said. The three have refused to talk with police about Bias' death.

Marshall previously had said he did not plan to subpoena Long, Gregg and Tribble because Maryland law grants automatic immunity to prosecution to those who testify before grand juries investigating drug crimes.

University of Maryland police found cut straws with cocaine residue, a small glass vial containing a small amount of cocaine and a glass pipe used for smoking cocaine in a trash dumpster outside of Bias' dormitory.

Investigators believe the drug paraphernalia came from Bias' room and that there had been drug use in the room before Bias collapsed, Marshall said.