Fernando Alonso says losing most of Friday’s first practice in Austin was “quite painful” as McLaren hoped to test several updates.
The double World Champion covered just four laps on Friday morning before a hydraulic leak kept him the pits.
McLaren were able to resolve the issue with the Spaniard on track in FP2.
“We lost the first session because of an hydraulic issue, which was quite painful because we had several items to test, including for next year,” said Alonso.
“We tried to catch up in the second session but it was difficult, so I think we’ll try them again in Mexico.”
He covered 28 laps in FP2 and finished the day with the seventh fastest lap time.
“I believe there’s still quite a bit to get out of the car – still some tenths to find, which I think probably everyone will find.
“We know [Max] Verstappen and [Nico] Hülkenberg have penalties, so if we manage to get into Q3, we’ll be able to start from an even better position.
“But if we don’t make it into Q3, and we can start eighth or ninth on new tyres, it could be very good too.”