Lewis Hamilton has admitted that he has been struggling with his Mercedes at the Bahrain Grand Prix.

The 2008 world champion will start from ninth after picking up a five-place grid penalty for changing his gearbox.

The Briton told Sky Sports News: "We made some changes to the car but I am still struggling with it.

"We had some troubles on Friday with the car which we fixed and going in to qualifying it wasn't looking too bad but once in qualifying I knew immediately, from the very first lap, that it wasn't going to be good. It just wasn't positive for me.

"A big congratulations to [teammate] Nico [Rosberg], he did a fantastic job. It's great to see him doing so well and he is such a strong competitor, pushing the team, asking tons of questions, and driving really, really well. I was unable to match him today but, who knows, maybe we can catch him tomorrow."

Rosberg will start tomorrow's race from pole position after recording the fastest time in qualifying.