Jenson Button struggling for soft-tyre pace in Brazilian Grand Prix practice

The Briton ended up only seventh in today's second session, where the best times were set on softs.

"We did some really good running this morning and at the start of the afternoon on the prime tyre - the car's working really well on the prime tyre actually," said Button.

"We tried a few different things, some worked, some didn't, but I think we understand why we are with the prime.

"The option tyre I struggled with massively. I couldn't get a lap on lap one, or at all, on low fuel with the tyre and on the long run I didn't have pace either.

"It's strange, with the balance I have it doesn't work for that tyre."

Button remains optimistic that McLaren will be able to find a solution before qualifying.

"We know some of the reasons, or we know what we can do to help some of the issues, and we just didn't have time to do it today," he said.

"The car works around here and we've made the soft tyre work all year, so I'm sure we can make it work."

Soft tyre issues aside, Button feels his form around Interlagos is looking good relative to recent years at the track.

"The car's felt good most of the day and I've been pretty happy with the balance," he said. "But I feel a lot better here today than I have here for many years, so I'm in pretty good shape."