Australia’s Smith was withdrawn on day five of the second Test after showing delayed symptoms from the 92mph Jofra Archer bouncer that struck him in the neck the previous afternoon.
The 30-year-old, who has scored 144, 142 and 92 in his three innings to date, was present at Australia’s training session in Leeds today but did not take any active part in proceedings.
Smith retired hurt after being floored but returned to complete his innings after less than an hour off the field.
He gave an unsteady performance, uncharacteristically missing a straight ball to fall lbw then calling for a review at the same time as walking to the pavilion.
At the time he had passed all necessary concussion testing but his condition deteriorated overnight and Marnus Labuschagne duly became Test cricket’s first concussion substitute.
Smith declared his intention to play at Headingley provided he was passed fit by medics, but given most guidelines on return-to-play protocols that always seemed unlikely.
As the Australia squad digested the news about Smith, nets continued on the pitch.
And there was no let up for the batsmen with Mitchell Starc sending down a series of quick bouncers at Labuschagne, who was hit on the helmet by one and was assessed by the team doctor before carrying on.