BAKU, Azerbaijan --A car setup choice left championship leader Max Verstappen struggling for performance during qualifying for the Azerbaijan Grand Prix, according to the reigning world champion.
Verstappen was sixth fastest in Saturday's session and failed to beat the qualifying lap time of Red Bull teammate Sergio Pérez, who qualified fourth, for the first time this year.
The three-time champion said he knew from his first lap in qualifying that a setup change made between final practice and Q1 had made the car more difficult to drive.
"As soon as I went out in Q1, the first lap, I just felt the car took a step back after we made some changes," Verstappen said. "The car became incredibly unpredictable, difficult, just because of the changes that we made.
"I'm a bit disappointed with that as you always try to optimise things and make it better. Unfortunately, I think we just tipped it over the edge.
"A shame that happened into qualifying.
"I never felt comfortable as the car was difficult. So when you're not comfortable, you can't attack corners, you're a bit under in it."
The lackluster qualifying result follows a sixth-place finish at the Italian Grand Prix two weeks ago, in which Verstappen said the team had turned his car into "a monster."
The Dutchman said he believes an upgrade to the floor has helped improve the Red Bull's underlying balance issues and addded the struggles in Baku were related to specific setup changes the team made to chase extra performance.
"We did improve the car [with the upgrade] but now with the setup we tried to perfect it, make a few things better but unfortunately it went the other way.
"We changed some things around and the car started jumping around a lot and you lose the [tyre's] contact patch with the tarmac."
McLaren driver Lando Norris cut 16 points from Verstappen's championship lead at the last two races, leaving his advantage at 62 points ahead of the Azerbaijan Grand Prix.
Norris starts Sunday's race from 17th on the grid, but Verstappen said the McLaren driver's misfortune had not change his approach to the weekend.
"But I still want to do well myself," he added. "And today was a bad day."