Docker reportedly overcooked a corner on a descent, lost control and crashed into a cutting just off the road.
Team doctor Dr Peter Barnes, who is with Docker in Melbourne said the head injuries were the biggest concern.
"Mitch has a minor fracture on his hand and his cheekbone, but neither require treatment," said Dr. Barnes. "He had a major concussion and for that reason he still needs to be under observation and further examination. I spoke to him this morning and he’s already feeling significantly better."
Matt White said the team's thoughts were with Docker at the stage 5 start of the Tour Down Under in McLaren Vale.
The Australian is expected to be released from intensive care, possibly as soon as this evening. It remains to be seen how long he'll be off the bike, though his spring Classic's campaign should not be in jeopardy.