The pair have both suffered knee injuries, with Silva possibly out for two weeks. "It is a big problem," admitted City manager Roberto Mancini. "Neither of them will be available.
"David has been an important player for us and has been doing well recently," he said. "Hopefully, he will be back for the Wolves game on 15 January. Mario might be back for the FA Cup tie at Leicester on Sunday."
Mancini also confirmed he is confident of securing the services of Bosnian striker Edin Dzeko from Wolfsburg. "We have agreed a fee," said the Italian. "He is a good player and all the teams in Europe want him. But we have an important game at Arsenal coming up and I will speak about him after that."
Meanwhile, Mancini claimed that his side are still outsiders in a five-team pursuit of the Premier League title. City are joint top with neighbours Manchester United, although they have played two games more. Mancini feels that City's inexperience in such situations could count against them.
"Arsenal, Chelsea, United and Tottenham all have more experience than us," he said. "Probably one of those four teams will win the title. We just want to work, so we can improve and try to keep getting better."