Atletico Madrid and Inter Milan have followed the six English sides in announcing their withdrawal from the proposed European Super League.
Breakaway European Super League founder and Juventus chairman Andrea Agnelli said on Wednesday that the league can no longer go ahead.
The 12 rebel clubs planning to form a European Super League are "ready for dialogue" with domestic leagues and UEFA, sources have told ESPN.
Gianni Infantino told the European Super League clubs that they could not be "half in, half out" of the established football system.
UEFA chief Aleksander Ceferin has accused the 12 clubs behind a proposed European Super League of "spitting in the face of football lovers."
Paris Saint-Germain midfielder Ander Herrera has become one of the first footballers to oppose a breakaway European Super League.
The 12 European clubs pursuing a Super League have told the leaders FIFA and UEFA that legal action is already being pursued.
Twelve of Europe's top clubs announced on Sunday they were launching a breakaway Super League, headed by Real Madrid president Florentino Perez.
Christian Eriksen's first league goal of the season earned Inter Milan a 1-1 draw at Napoli on Sunday, moving the league leaders nine points clear.
AS Roma's hopes of a top-four finish were dealt a major blow as they slipped to a 3-1 defeat by Serie A strugglers Torino on Sunday.
Juventus slipped to a last-gasp 1-0 defeat at Atalanta on Sunday as Gian Piero Gasperini's side leapfrogged the champions into third place.
Fifteen of Europe's biggest clubs are in talks to launch a European Super League with a $6 billion fund backing the project, sources told ESPN.
AC Milan secured a first home Serie A win for over two months with a nervy 2-1 victory over Genoa on Sunday.