Talks over pay and other conditions between National Football League (NFL) team owners and players have broken down, threatening the 2011 season.
The players’ association, the NFLPA, has said it will “decertify”, in effect renouncing its status as a union and becoming a trade association instead.
Therefore arrangements made in the past between the union and the NFL would no longer be immune to competition law.
It means individual players could file anti-trust lawsuits against the NFL.
Any work stoppage would be the league’s first since 1987. The new season is due to start in September.