Polak is placed into an induced coma at the Alfred Hospital after suffering bruising to the brain.

Doctors describe Polak as being in a critical, but stable condition. Polak is not expected to play football again this season.

"In terms of footy, it is unquestionable. He won't play this season - longer term beyond that, we'll just have to wait and see," Dr. Greg Hickey of the Alfred Hospital said.

Polak's condition continues to improve from critical to satisfactory as he responds well to tests and to family members who have travelled from Perth to be with him.