Valtteri Bottas could sit out the Australian grand prix.
The Finn, who qualified three places behind his Williams teammate Felipe Massa on Saturday, was seen limping in the paddock immediately after the session.
Engineer Rob Smedley confirmed he began complaining of lower back pain during qualifying.
Williams said the 25-year-old driver went to be “checked by FIA doctors”.
Shortly afterwards, it emerged he had gone to hospital for further tests.
Asked if Bottas might have to sit out Sunday’s Australian grand prix, a spokeswoman for the Grove based team admitted: “It could go either way.”
“It was great to finally start the season and to have a very tight qualifying session. The car performed well and we were fighting with Ferrari throughout.” Valtteri Bottas said, Williams official press reported
“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.”