Manchester City boss Roberto Mancini is believed to have failed in his attempt to hold on to Kolo and Yaya Toure before they depart for the African Cup of Nations.
The Italian manager is believed to have initially requested that the Ivorian brothers delay their exit until January 16. However, it is expected that the pair will leave after the Premier League leaders' FA Cup third-round tie with Manchester United.
"It is difficult but I think they will leave us after United," The Express quotes Mancini as saying. "We have talked with their manager three days ago and will talk again with the Ivory Coast president. We will try but it is difficult."
Mancini also stated that the North West side will have to offload players before they enter the January transfer market.
"We should sell some of our players before we do anything," he added. "After that maybe we can do something but at the moment there is nothing."
City travel to the Hawthorns to take on West Bromwich Albion on Boxing Day.