A limping Valtteri Bottas ended qualifying with a sore back.
The 25-year-old Finn, who qualified three places behind his Williams teammate Felipe Massa in Melbourne, was seen limping in the paddock after the decisive session on Saturday evening.
"Valtteri was suffering with his back and lost a lot of time at the last corner," said Williams engineer Rob Smedley.
“We don’t know what it was, he just started complaining about it in the middle of the second qualifying saying that the small of his back was hurting. We had a look behind his him and his seat and there was nothing in there. So I don’t know if he has jarred his back or something.”