Manchester City duo Yaya and Kolo Toure appear set to miss Sunday's FA Cup tie against Manchester United after a bid to delay their Africa Cup of Nations call-up was rejected by Ivory Coast coach Francois Zahoui.
City manager Roberto Mancini said on Thursday he hoped the brothers' departure for international duty could be put back, thereby allowing them to feature for the cup holders and Premier League leaders in the stand-out tie of the third round.
However, playing in the Manchester derby at Eastlands this weekend would mean the Toures miss an Ivory Coast meeting in Paris on Saturday, where the squad is assembling before flying out to Abu Dhabi for a two-week training camp.
Zahoui told BBC Africa on Thursday: "Clubs know the rules.
"I'm expecting them (the Toures) for the FIFA deadline."
Under FIFA rules, players can be called up by their countries two weeks before the competition, which starts on January 21.
Zahoui added: "The national team in Ivory Coast is led by people who are well educated and I was surprised that people in England think that we don't know the FIFA rules about dates.
"(Arsenal manager) Arsene Wenger was my coach (at French club Nancy) so we have a close, respectful relationship.
"But even with him I said that the head of the Ivorian federation won't mess about. Don't turn this into a stand-off."