MINNEAPOLIS — A Minnesota judge has ruled that Vikings coach Brad Childress can be called as a witness in the labor dispute between two of his players and the National Football League.

Hennepin County Judge Gary Larson's ruling came Monday as trial began in a lawsuit against the NFL by Vikings linemen Kevin and Pat Williams.

The players are suing the league over its anti-doping policies after the league tried to suspend them in 2008 for testing positive for a banned diuretic. The trial in Minneapolis is expected to settle some key labor issues, including whether the players work for the NFL, the team, or both.

The players' attorney, Peter Ginsberg, says Childress will testify that he was one of the few people outside the NFL who knew of the positive test and that he didn't tell anyone in the media. The players contend the NFL broke a state confidentiality law in disclosing the tests, something the league denies.