Nico Rosberg says his chances of winning the Monaco Grand Prix will come down to how much Mercedes has improved its tire wear.
Despite taking his third pole position in a row, the German is keeping his optimism in check ahead of Sunday's race, citing his car's tire-chewing performance in Spain two weeks ago as a genuine concern.
"I'm happy to be starting first, [but] in Barcelona we were struggling a lot in the race, [finishing] 70 seconds behind the race winner. We are improving, but it is difficult to understand the tires and get the most out of them. We're improving step by step, but there are still a lot of questions marks remaining.
"It will be difficult tomorrow, it is our weakness. Hopefully better than Barcelona, but it is still a weakness. It could also be a bit better than expected."
Rosberg added that the start will be key, and that getting through the first corner in the lead is a must.
"The start will be important, to get to the first corner first," he said. "I have the advantage as I am first, after that we have to see how it goes, who is quickest with strategy."