Despite investing millions in the summer, City are struggling to make an impact and have collected only one win bonus in four league games.
A club who view the Champions League arena as the next step are already seven points behind leaders Chelsea.
The teams are due to meet at Eastlands a week on Saturday - one of a number of crucial games, according to Mancini, whose side also face Wigan and Newcastle in the league as well as Salzburg on Thursday in the Europa League, then Juventus.
Wayne Bridge, Jerome Boateng, Aleksandar Kolarov and Mario Balotelli are sat out the 1-1 draw against Blackburn on Saturday. So too did Nigel De Jong (dead leg) and Emmanuel Adebayor (hamstring) because of injuries - but both could travel to Salzburg.
Mancini said: "De Jong was injured on Friday with the very last kick of training. Adebayor's injury came a week ago but I think they should be ok for the next game.
"We have a difficult month until the next international break, we need to get some of our injured players back and win these next six games."
Source: PA
Source: PA