MINNEAPOLIS — The Minnesota state lawsuit over the NFL's suspensions of Vikings players Kevin Williams and Pat Williams will go to trial next month.

Hennepin County District Court Judge Gary Larson ruled Thursday that there are several outstanding questions on employment issues, so the trial will start March 8.

The Williamses were suspended for four games after testing positive in 2008 for a banned substance that can mask the presence of steroids. They sued the NFL, arguing the testing violated Minnesota labor laws.

Larson says it's unclear whether the Vikings or NFL — or both — are the players' employer under state law.

The NFL has argued that federal labor law should pre-empt state law because uniform standards are necessary nationwide. But Larson says many corporations have employees in multiple states and they comply with state laws.