The Mexican ended Friday running in P11 and P16 in FP1 and FP2 respectively however insisted that there was underlying pace in the car.
Speaking after stepping out of the car, Perez said that even without any upgrades on the car this weekend, the team had reason to be optimistic about its chances.
“The new tarmac was very dirty this morning and there was big track evolution during the day," he said.
"That’s why we saw so many cars struggling this morning and a few spins.
"We worked on understanding the current package because we don’t have big upgrades for this race. So we just tried to find a balance that I’m happy with and evaluated some of the things we’ve added to the car over the last few events.
"I can feel the potential in the car and we are making improvements, but we need to make a good step tonight.”