 Complete the following phrase:  In September 2014, it was announced that Bottas and Massa would retain their drives with Williams for the season. At the opening race of the season in Australia, Bottas qualified sixth for the race, but injured his back during qualifying. He was taken to The Alfred Hospital for precautionary checks, where he was diagnosed with soft tissue damage to his lower back, and was not medically cleared to race. Both Bottass and Williamss season did not live up to their hopes. Williams lost out in the development war to Ferrari over the winter and slipped further behind Mercedes. Bottas achieved two podium finishes across the 2015 season. The first came at the 