Red Bull have been unceasingly rapid this season, giving Verstappen free reign over the rest of the field as he stamped his authority in the Drivers' Championship by opening a 109-point lead over Leclerc.
As Scuderia's home Grand Prix, nothing would please the Ferrari team more than to win at the Monza circuit, but according to Leclerc it seems unlikely.
"I think it's going to be a bit of a difficult weekend. On paper at least it's going to be a difficult weekend," he said during the pre-event press conference on Thursday.
"We expect Red Bull to be stronger. The track characteristics don't fit exactly our cars.
"But again, we've had some good and bad surprises this year, so hopefully this one is one of the good ones and that we overperform compared to what we expect.
"I think comparing to Red Bull especially, because it's a bit more consistent through the whole year, we are slower down the straights.
"Their main strength this year is the straight-line speed. We seem to be a little quicker in the corners, but on tracks like here it's not enough to gain back the advantage that they have on the straights."
The Frenchman is well aware of Red Bull's speed, while also revealing that Mercedes is more of an unknown quantity this season, as their performances seem to vary significantly between tracks.
"Compared to Red Bull I think this will be the case this weekend," he added. "Compared to Mercedes it is difficult to make predictions for this weekend, they have had ups and downs."