Yaya has opened up about his family's loss by claiming that City officials did not allow him to stay by his brother's bedside for an extra few days while he was sick.
In an interview with France Football, Yaya said: "I confess that I am still very sad. I¹m suffering because I feel I have done nothing useful for him the last few weeks.
"At the end of the season, I wanted to stay for four or five days with my brother before I flew to prepare for the World Cup with Ivory Coast, except that City did not want to give me a few days.
"I went to celebrate the title championship in Abu Dhabi while my brother was in his sickbed. By fortune, Kolo was at his bedside. After that I blame myself for not insisting and for not leading them to respect me."
Ivory Coast are currently at the top of Group D at the World Cup.