Peter Edward Rose (plaintiff) is employed as a Field Manager for the Cincinnati Reds (Reds) (defendant) baseball team. Allegations arose that Rose was wagering on Major League Baseball (MLB) games, in contravention of the rules of MLB (defendant). Commissioner of Baseball A. Bartlett Giamatti (defendant) scheduled a disciplinary hearing concerning these allegations for June 26, 1989. On June 19, Rose filed an action in the Court of Common Pleas of Hamilton County, Ohio, against Giamatti, MLB, and the Reds. Rose sought a temporary restraining order and a preliminary injunction preventing Giamatti from holding the disciplinary hearing. On July 3, Giamatti filed a notice of removal to federal court on the basis of diversity jurisdiction. On July 5, Rose moved to remand the case back to the court of common pleas. Rose argued that, because Rose, MLB, and the Reds were citizens of Ohio, there was a lack of diversity among the parties.