Pucovski got hit on the helmet late in the match against India, played at the Drummoyne Oval.
The concussion is his ninth so far and puts a hold on his likely Test debut.
Warner suffered a groin strain in the second ODI and hasn’t recovered fully.
He is the first player from the Australian side to be ruled out for the first Test.
Both players are still unsure for future Tests as news is out only regarding the first game.
Marcus Harris has come into the Australian side as a replacement.
He has played nine Tests, and like Pucovski, is still finding his feet in international Cricket.
He opened the batting last time India toured and made his debut in the same series.
He did a decent job in that series with two half-centuries and was one of the Australian sides’ better players.
He went on to play in the ashes but struggled against the pace attack.
With a challenging tour of England, Harris worked with Chris Rogers and made some adjustments to his technique.
He is also performing well in the Sheffield Shield, which helped him get into the Australian A side to face India.
Marcus Harris has shown he is a quality batsman, and his inclusion could be a blessing with Joe Burns struggling to find form.
With Marcus returning, the potential option of Marnus Labuschagne opening may be complicated with the presence of a specialist opener in the squad.
To add to the injury woes, Cameron Green has also suffered a head injury in the second practice game.
Bowling to Bumrah, Green took a ball to the head after a well-timed straight hit.
It was a severe blow, and Green is now out of the game.
His availability for the first Test is still uncertain and may take time to find out.
Sean Abbott, one of the back-up seamers, is also a concern after a calf issue.
He managed just seven overs, and a scan later said it was the tightness and not a calf tear.
Though he is an unlikely starter, an injury may still complicate things for Australia.
David Warner’s injury remains the high profile one, but Will Pucovski’s end’s a few debates temporarily.
A few weeks ago, there have been discussions on the opening pair.
With Warner fit, his opening partner was in question.
Pucovski put in some good numbers in the domestic season, while Burns has the experience and has opened with Warner in the past.
Though he formed a good partnership at the top, Burns has been struggling with low scores over of late.
With the lack of runs, Will Pucovski looked a likely candidate, and it remained a tough decision to make.
Once Warner was ruled out, Will Pucovski was in line to make his Test debut, giving Burns another chance to prove himself.
Both contenders looked set to open together for the first Test.
With another concussion to Will Pucovski, the equation differed.
Burns now remains at the top, while Marcus Harris joins him.
It is now an opportunity for both batsmen to prove who stays once Warner returns.
The situation becomes more challenging for Will Pucovski, as he now has to contend with both Burns and Harris.
Before his injury, it was just Burns who challenged his spot.
With a good performance from either opener, the competition will now get tighter, as Warner returns for the second Test.
Showing good form in the limited-overs leg, Warner has all but sealed his place, and it leaves one spot for three players to contend.
In case of any more injuries, Australia has the likes of Shaun Marsh and Usman Khawaja waiting.
Both batsmen have been out of the side for a while.
In case more players are ruled out, they have experienced hands to walk in.