Lewis Hamilton has said that he is expecting a "tough battle" for his Mercedes team in Sunday's Bahrain Grand Prix.
The British driver finished 10th-fastest in second practice on Friday, 0.822 seconds off Lotus driver Kimi Raikkonen, who set the fastest time.
Hamilton told BBC Sport: "I don't think we are as far off as it looks. I think other people were on different fuel loads.
"It looks like we're 0.6 seconds off the pace. I think it's maybe half that; maybe a bit less. But it will be a tough battle for sure this weekend."
Hamilton finished third in last weekend's Chinese Grand Prix.