Brake concerns for Toyota
The Italian headed the Japanese team's first ever front-row lockout in the Sakhir desert, but revealed afterwards that his brakes were not working properly.
"I was struggling with the brakes, the pedal was getting long and I was not able to brake the way I wanted," said Trulli, who also put his Toyota on pole with very light fuel at Indianapolis in 2005.
The problem did not stop the 34-year-old from emerging quickest from Q3, but admitted he is concerned ahead of Sunday's 57-lap race.
"We need to analyse the data to see if we have a problem with the brakes, it is a bit of a worry," Trulli said on Saturday.
Another worry might be strategy, which will become clearer when the FIA publishes the car weights later this afternoon.
Red Bull's Christian Horner said after qualifying: "I think they (the Toyotas) might be three-stopping. We'll find out later I suppose."