Lewis Hamilton has said that Mercedes will need to improve his car if he is to challenge for pole position at the British Grand Prix.
The 2008 world champion had limited time on track during today's practice sessions, with teams unwilling to risk their cars during wet conditions at Silverstone.
The 28-year-old told Sky Sports News: "We had quite a challenging day today and definitely have more to learn tomorrow. I'm struggling a little with the balance of my car so there's some work to do overnight to get us into shape for qualifying.
"We haven't quite got it hooked up yet and you can really tell that on this circuit, particularly with Becketts and Maggots. I'm confident we'll fix it tomorrow though."
Hamilton is currently fourth in the drivers' standings.