For the past couple of years, there has been talk of establishing a breakaway European Super League, which would basically replace the Champions League. But FIFA wants to squash this potential dissent before it can gain any real momentum, and the global football governing body released a statement saying that the Super League would not be officially recognized and that any players who participated in the league would be banned from all competition organized by FIFA, including the World Cup.
"Any club or player involved in such a competition would as a consequence not be allowed to participate in any competition organised by FIFA or their respective confederation," the statement said.
The joint statement was made by FIFA and the major continental confederations, including UEFA, so players who joined the Super League would be banned from all international football, beyond just the World Cup. Continental tournaments like the European Championship, Copa America, CONCACAF Gold Cup and UEFA Nations League would also be off-limits.
So far, most European clubs have denied any involvement in the creation of a Super League, but German magazine Der Spiegel reported in 2018 that Spanish club Real Madrid had made plans regarding the creation of a Super League that would include most major clubs in Europe. Real president Florentino Perez has long cited the need for European tournament play to change but has not confirmed plans of a Super League.
Typically, this sort of talk is primarily seen as negotiating tactics by clubs, but the joint statement from FIFA could indicate that the formation of a Super League could really happen.