Marcus Harris could be a contender for opening slot but not Tim Paine as he never opened the inning, he's more of middle-lower middle batsman. Both teams are having tough time on selection.
For Australia Top order and Cameron Green's concussion seems serious drama and India is also confused over Shaw vs Gill / Pant vs Saha and 4 seam bowler attack vs 3 seam + 1 spinner.
The latest news is that Cameron Green will make his test debut if he passes the fitness test. Regarding Shaw vs Gill, I don't have a preference. I am not impressed by both the players so far in this tour. That said, I would pick Pant over Saha. The latter is 36 years old and I think picking him over a promising player such as Pant will affect the morale of the younger players. And as far as the bowling attack is concerned, would rather prefer 4 pacers. Indications are that the track at Adelaide will be more supportive towards the pace bowlers.
Earlier i had doubt over Cameron Green but after Will Pucovski concussion Green do have solid claim in the Playing XI, hopefully he clears the concussion test and earn his Test cap, he deserve it. I am fan of both Shaw and Gill but as of now Shaw seems to be in pretty bad phase, his shot selection is not looking great atm, on the other hand Gill looking good so would prefer Gill over Shaw.
On second thought India could try Vihari at the top order, he did open for Indian in the last tour and impressed many with his gritty innings. In SENA countries i would always prefer Pant over Saha because Pant is better batsman. There is no doubt that Saha is superior keeper than Pant but in SENA countries spin doesn't play big part and so far Pant did excellent job behind the wicket with our fast bowlers. If it was subcontinent pitch then Saha's selection makes much more sense but we never know what kohli and Shastri are up to?
I think India may go with Bumrah-Shami-Umesh-Ashwin combination.
My team for D/N testMayank
Gill /Vihari (Open or 6th spot)
Pujara
Virat
Rahane
Gill/Vihari (6th spot or Open)
Pant
Ashwin
Umesh
Shami
Bumrah