Manchester City playmaker David Silva could be back in action next weekend after suffering a hamstring injury on Spain duty, but he will miss matches against West Brom and Ajax.
Silva will definitely miss Saturday's Premier League clash at West Brom and Wednesday's vital Champions League encounter with Ajax but could face Swansea the following Saturday.
Mancini said: "He is not ready for Saturday, and will not be for the Champions League, but we hope for the next game against Swansea."
England players Joe Hart, Joleon Lescott and James Milner returned to City later than expected after their World Cup qualifier in Poland was put back from Tuesday to Wednesday.
Despite the disruption to his preparations, Mancini has no concerns about their condition.
The Italian said: "The English players who played on Wednesday are tired but I am not worried, they have another day to recover."