Lando Norris feels McLaren do not have the same outright pace at the Emilia Romagna GP compared to their speed at the season-opener in Bahrain.
Norris finished eighth in the second practice session in Imola but failed to show any glimpses of matching some of his midfield rivals.
"I made a couple of mistakes, went across the gravel one time so it's a tricky track to kind of get a good rhythm with and to put the whole lap together and so on," Norris told RacingNews365.com and other select members of the press.
"We made some improvements with the car from FP1 to FP2 and we'll try to make some some further ones for FP3.
"We're still learning about the car and the strengths and weaknesses where we still need to improve. This track is very different to Bahrain, the track surface is very different as well so how the tyres work, how the car works is very different."
Norris revealed McLaren were testing some new parts on the MCL35M since the three week break from Bahrain has allowed the team to bring upgrades to Imola.
"We have test items on the car so we're kind of comparing things between the different runs and different sessions," said Norris. "I managed to do a bit more high-fuel long-run stuff which we didn't get to do in FP1.
"I think the cars potential if you can put it all together. I think it's maybe not as easy as what it was in Bahrain to put it all together, and we're maybe not quite as quick outright as what we were in Bahrain.
Norris believes getting into Q3 will be crucial given the difficulty of overtaking at Imola due to the medium and high speed turns.
"I think we can put in a good performance tomorrow if we can get it right but we've got some hard work tonight, to review everything and put it all together," added Norris.
"It looks very close. I think Ferrari are a good step stronger than they were in Bahrain. AlphaTauri are looking very fast so it's going to be tricky.
"It's quite a qualifying dependent track so there's gonna be a lot of focus on trying to maximise the performance over one lap and maybe compromise a little bit more in the race.