Manchester United co-chairman Joel Glazer was one English Premier League personality who apologized for his club's involvement in the abandoned European Super League deemed controversial due to its similarities to aspects of American sports, particularly its lack of promotion and relegation. 

Per Rob Dawson of ESPN, that apology did not prevent a group of protestors from breaking into United's training ground last week. Dawson now notes things could get worse ahead of and possibly during Sunday's clash between rivals United and Liverpool. 

According to the ESPN story, roughly 10,000 supporters are expected to participate in an anti-Glazer protest outside Old Trafford ahead of the Liverpool contest, and it's feared some may attempt to block team buses or find a different way to force the game's postponement.