The Manchester City manager is concerned his squad will struggle to cope with injuries and players leaving for the Africa Cup of Nations, and has ruled out selling any players.
It has been suggested that Mario Balotelli could be on his way back to Milan while the Toure brothers - Yaya and Kolo - will be away on international duty for four weeks.
When asked if he might consider investing in new faces, Mancini said: "Probably. We can't sell players. We don't have enough players to play if we sell players.
"We can have a problem because we lose three players and we have Micah Richards, I don't think he play until the end of February.
"Jack Rodwell - we don't know when he can play. Maybe we can recover Aleksandar Kolarov in two weeks. We will see this in next days."
Maicon has also been receiving treatment for a knee injury in Italy while Balotelli is not expected to return from a virus until the Watford game.
Edin Dzeko is expected to retain his place in the side against Stoke after scoring twice in the 4-3 win at Norwich.
"If he scores two goals very game we don't have a problem," Mancini added. "I am happy for Edin because I think he deserves to score.
"He scored two goals but he did also a good performance. I hope he can continue to score and play well."