The 2006 collective bargaining agreement (CBA) between the National Football League (NFL) (defendant) and the NFL Players Association, the labor organization for the players, incorporated a policy against the use of anabolic steroids and other substances (the Policy). The Policy prohibited football players from using a number of substances, including “blocking” or “masking agents” such as “diuretics or water pills” and required all players to be responsible for what was in their bodies. Any prohibited substance located within a player’s body resulted in remedial action, even if the player was unaware he was taking a prohibited substance. Five professional football players, including Pat Williams (plaintiff) of the Minnesota Vikings, tested positive for bumetanide, a prescription diuretic and masking agent, in violation of the Policy. The substance was an ingredient in the supplement StarCaps, although it was not listed on the product’s label. StarCaps was not specifically banned under the Policy. After testing positive for bumetanide, Williams and the other players were notified of the results by letter and were suspended without pay for four games. All of the players appealed the suspensions which were upheld by Jeffrey Pash, Vice President and General Counsel for the NFL. The players filed suit in Minnesota state court seeking to have Pash’s decision vacated, and the NFL removed the matter to federal court. The players included claims for violations of Minnesota’s Drug and Alcohol Testing in the Workplace Act (DATWA) and other various state-law and tort claims. The district court granted a preliminary injunction which allowed the players to play in the otherwise suspended games while the case proceeded. Further, the court held that the players’ claims under Minnesota law were not preempted by Section 301 and the LMRA. Both parties appealed various portions of the court’s decision.