McLaren is facing a difficult weekend according to Sergio Perez, while team-mate Jenson Button was left perplexed by the behaviour of the Pirelli tyres.
Button was eleventh fastest in second practice, with Perez two tenths further back in thirteenth.
"It’s very difficult to know exactly what to do with set-up. This is a big traction circuit, with lots of low-speed exits and a few high-speed corners too, and that puts a lot of load into the rear tyres," said Button.
"The tyres are behaving a bit strangely here – driving conservatively doesn’t seem to help their wear-life, so there’s only so much you can do without damaging your outright pace."
Perez believes that while fighting for Q3 will be tough, aiming for a points is a realistic target.
"We managed to complete our full run-plan in both the morning and afternoon, which was a positive, but it’s going to be a difficult weekend for us," said the Mexican.
"Although we’ll probably be fighting to get into Q3, there’s still plenty of potential for having a good race on Sunday. The team has shown before that, with solid preparation, we can run a clever strategy on Sunday, and I think we have enough raw material from today to help us race strongly this weekend."
"So, scoring points is a realistic ambition for us here in Bahrain."