Chelsea are by no means alone when it comes to this sort of breach and some of the world's biggest clubs have previously been implicated. Liga giants Barcelona, Real Madrid and Atletico Madrid were all sanctioned by FIFA for similar regulation breaches, with the governing body imposing similar two-window bans. However, while Chelsea's breaches concern the cases of 29 minors, the cases of the Spanish clubs involved many more players. In the case of Barcelona, 31 minors were investigated and Real Madrid's case saw the investigation of 70 minors. However, Atletico's breaches involved more than double the Clasico pair combined, with 221 investigations.