The R's host City at the West London venue tomorrow and the Italian tactician is expecting a very strong showing from Neil Warnock's men in front of their loyal fans.
"They are a different team at home, a very strong team at home and we need to play very well if we want to win there," Mancini said.
"We will try to attack but it's not all down to us - there is always another team, and we need to play very well.
"They also have some very good, experienced players and they beat Chelsea in their last home game, so they deserve respect and have made a very good start this season.
"Loftus Road is a tight, compact ground and it will be hard if we are not at our very best."