Jenson Button has said that he does not expect to be racing at the front of the field at this weekend's Chinese Grand Prix.
The 2009 Formula 1 world champion recorded the sixth-fastest time during the second practice session earlier today, while McLaren teammate Sergio Perez finished 11th.
The Briton said in a statement released by the team: "We can't yet conclusively tell if the upgrades we brought to this race have improved the car.
"They're perhaps not as big a step forward as we'd expected, the issues with the car are still there, but the car does feel a little bit better.
"I don't think we'll be fighting at the front this weekend, but we'll definitely be fighting someone."
Button is 13th in the drivers' standings, having secured two championship points in the opening two races of the season.