Bottas is set to line up sixth on the grid for the 2015 season-opener despite being in pain during Q2 and Q3. The Finn was taken to hospital to have his back checked out shortly after qualifying concluded.
"It was great to finally start the season and to have a very tight qualifying session," Bottas said. "The car performed well and we were fighting with Ferrari throughout.
"Unfortunately towards the end of Q2 I started to feel a pain in my back. Under the circumstances I'm happy with sixth place, but as Felipe proved, this is not a true indication of our pace. Given the back complaint I had during the session, the team and I felt it sensible to get me checked out at the local hospital and we await their diagnosis."
Williams subsequently tweeted: "[Bottas] will rest at his hotel tonight & be checked in the morning by medics before any decision is made."