Though the U.S. Open Cup soccer tournament dates to 1914, it is usually seen as a less important sideshow to Major League Soccer’s season and M.L.S. Cup. Fans and organizers of the tournament are always looking to increase its profile and get a bigger place on the national sports map.

Well, now the U.S. Open Cup is making news, but maybe not of the most favorable kind.

On Wednesday night, Los Angeles F.C. defeated the visiting Portland Timbers, 3-2, in a quarterfinal match. Or did they?

On Thursday morning, Portland officially protested, saying L.A.F.C. had broken rules by using too many foreign players. Now L.A.F.C. could even face disqualification from the tournament.

M.L.S. has always had ever-changing, sometimes complicated rules about the number of foreign players permitted, in part to help boost American soccer. Teams are currently allowed eight international players on their roster, and can trade for more.