Lando Norris admitted he was "not comfortable" despite being fastest in the Belgian Grand Prix second practice.
McLaren finished first and second on Friday, with Norris finishing just 0.215 seconds ahead of team-mate Oscar Piastri.
Max Verstappen finished third, but despite an impressive performance, his 10-place grid penalty will affect his result.
Norris finished second in the Hungarian Grand Prix last week, behind Piastri, in a race overshadowed by a radio spat between the Brit and the pit wall.
Having put that behind him, even after a confident practice session on Friday, Norris is not willing to rest on his laurels with Red Bull showing their threat.
"Red Bull are very quick at the minute," Norris said. "So, tricky, but I've just not felt very comfortable today with the car.
"So hopefully I just wake up [on Saturday] and feel a bit more comfortable with it. But we'll try and improve a few things and see again.
"I know it looked good on the timesheets, but I've not felt super comfortable in just going out and doing it. So, hopefully, I can just get in a bit more of a rhythm and feel a bit better out there."
A great way to end our Friday. #BelgiumGP ?? pic.twitter.com/yr5gJzmuQP
— McLaren (@McLarenF1) July 26, 2024
Meanwhile, Lewis Hamilton finished in 10th after struggling to match the pace set in the second session.
Mercedes have been credited for their improvement in recent weeks, with Hamilton winning at Silverstone before finishing third at Hungaroring last Sunday.
However, he was also left disappointed on Friday and said he was hoping for the forecast rain over the rest of the weekend to give the team more of an edge.
"It was a pretty bad day," Hamilton said.
"I don't really know what to say! Obviously, it's been feeling great in the past couple of races, but it just felt completely different today.
"We worked on it. The first session was not great, but then in the second session we made some changes, and it started off great, and then when I got to the soft tyre I just couldn't improve and there were a bunch of balance issues we had through the lap.
"It was better through this session, but everyone else went even better. So, to be 1.2s behind is not great.
"If it rains, then that opens it up a little bit and, hopefully, we can do a better job. I think the car should be better in the wet than it is in the dry."