Based on statements made by Michael B. Nifong, the Durham County district attorney, the lawyers are bracing for him to bring a case to a grand jury that meets on Monday. That move, they said, would inevitably produce an indictment of a player on sexual assault charges, and perhaps an indictment of other players on charges of aiding and abetting the assault. An arrest warrant would be issued for any players who are indicted. After Monday, the grand jury here is not scheduled to meet again for two weeks.