Robinho expected to return to the club following Brazil's game against the USA.
But they now face the embarrassment of having to leave the most expensive player in the history of British football off their 25-man list.
Roberto Mancini said: "I think it's better for the other players to find another solution, other teams, because it's better for players to play. Robinho will come back here. I will speak with him and then together we can decide."