Australia hopeful Cameron Green appears doubtful for the first Test of the upcoming series against India after he suffered concussion.

During his second spell of the day-night tour game against India at the SCG, Australia A all-rounder Green had to be subbed out of the match after he was struck in the head while bowling.

Green was hit by a clubbed straight drive from Jasprit Bumrah, with Cricket Australia subsequently confirming the 21-year-old had sustained a "mild" concussion.

The youngster was unable to react to the shot and the ball hit him on the right side of the head, with non-striker Mohammed Siraj immediately rushing to check on the bowler, who was assessed on the field for several minutes before he left for further checks in the dressing room.

Green has now been ruled out for the remainder of the tour match, casting doubt over his availability for the first Test in Adelaide, which starts on December 17.

CA team doctor Pip Inge said: "This is Cameron’s first concussion. He has returned to the team hotel and will not play the remaining two days of the tour match.

"We will continue to monitor him and provide an update on his condition in due course."

Green's injury follows on from a similar incident in the previous tour game, with Will Pucovski diagnosed with mild concussion after being struck while batting.

Pucovski, who seemed a likely candidate to replace the injured David Warner for the Adelaide Test, is now waiting on the results of further assessments.

Last month saw the sixth anniversary of Phillip Hughes' death due to a head injury sustained in a Sheffield Shield match at the Sydney Cricket Ground.

The Australia batsman was hit in the neck by a bouncer, resulting in a haemorrhage of blood into the brain, on November 25, 2014, and died two days later.