Steve Smith remains in doubt to play for Australia in the third Ashes Test at Headingley starting on Thursday.
The Sutherland batsman is in a race against the clock to prove his fitness after he was diagnosed with delayed concussion following being struck by a bouncer on day four of the second Test at Lord's.
Smith was hit in the side of the neck having already been struck on the arm during a vicious spell of fast bowling from England quick Jofra Archer.
Smith left the field before returning to continue his innings. He was dismissed for 92 before being part of the first concussion substitution in the history of Test cricket when he was replaced by Marnus Labuschagne for the final day's play.
Australia were to know by Tuesday whether Smith would be available to play. Smith was required to train in Leeds and then face the team's reserve fast bowlers in a net session on Wednesday as well as pass concussion tests.
Smith reportedly told teammates he was feeling better on Monday as the Australian team traveled to Yorkshire via bus.
Grogginess and a headache had led team doctor Richard Saw to diagnose Smith with delayed concussion on Sunday.
"[I] started to feel a bit of a headache coming on [Saturday] night. Probably as the adrenaline got out of my system," Smith said.
"[I] was able to get a good sleep in which is somewhat rare for me. But woke up feeling a little bit groggy and with a headache again.
"[I] had some tests done and upon some further assessments deemed to be a mild concussion unfortunately.
"Obviously it's a quick turnaround between Test matches.
"I'm going to be assessed over the next [few] days, probably a couple of times a day to see how I'm feeling and progressing.
"I'm hopeful that I will be available for that Test match.
"But it's certainly up to the medical staff and we'll have conversations.
"It's certainly an area of concern concussion and I want to be 100 per cent fit."
The call on whether Smith has recovered to play will be made by Saw.
Smith also indicated he may start using a clip-on attachment to his helmet for additional protection, which were developed following Australian cricketer Phillip Hughes' death in 2014.
Smith has not previously used them but the incident at Lord's has led him to re-consider that stance.
"I, along with a few other players in the team, find it a little bit different [and] uncomfortable," Smith said of the neck guard.
''But it's certainly something I need to probably have a look at and perhaps try in the nets and see if I can find a way to get comfortable with it.''
