Max Verstappen has opted for a higher downforce package for race day compared to team Daniel Ricciardo but is unsure the choice will bear fruit.
Red Bull Racing ran different set-ups in the morning practice and in qualifying for its drivers - Ricciardo had the T-wing fitted to his RB13, whereas Verstappen ran without it.
The Dutchman qualified P5, just 0.026s behind his team mate. But his performance tomorrow may depend on track temperature and levels of degradation.
"After my first Q3 run I was definitely not happy, so I was happy afterwards that my second run was decent, and we can work from here," said Verstappen.
"We chose between the two cars to do different strategies, one with more downforce, one less. I was with more.
"If it's the right one I'm not sure. Maybe I should say now it's not but maybe tomorrow it is. It's a bit difficult to say."
Higher temperatures could lead to higher degradation levels for those - like Ricciardo - running less downforce, conditions which could play right into the 20-year-old's hands.
"Tomorrow it's going to be quite a bit warmer, more degradation from the tyres, so we'll see. here in the first sector, when you start to struggle it's really painful.
"I just hope I'll have bit more rear load on the car tomorrow. Hopefully its gets really warm and we get the degradation."
Asked by reigning world champion Nico Rosberg during his Sky F1 interview whu he appeared to struggle at Suzuka, Verstappen pointed to the cornering speed of F1's new-spec cars.
"More corners are flat out this year and a lot faster," he said.
"So it becomes more of a straight, it's a bit more painful for us. Also it's not as warm as in Malaysia, so it seems like we don't have that advantage like we had there"