It is Christmas eve. The festive spirit might have encouraged India to put behind them the three-day knockout in Adelaide. But interim captain Ajinkya Rahane and head coach Ravi Shastri have to deal with several questions concerning what their best XI for the Boxing Day Test will be. It is a tough ask for India considering they will miss Virat Kohli, who is back in India on paternity leave, as well as Mohammed Shami, who is out of the series with a broken arm.

Here are some of the key questions India will have to answer.

Drop or retain Prithvi Shaw?

From his backlift to his footwork, experts have picked holes in Shaw's technique after the opener, playing only his first Test in Australia, was bowled twice in Adelaide in the space of six balls. Shaw has already made two ducks in the six innings he has batted in so far on this tour if you include the two warm-up matches the Indians played against Australia A. Still, Shaw would want to be judged after a longer trial. Should he get that?

Pros: Shaw's strength is the blistering pace at which he scores once he gets a start. A first-class average of 51.43 and strike rate of 80.96 and a century on Test debut support the idea that the 21-year-old Shaw is that rare talent that experts from around the world believe he is. Although Melbourne also has a drop-in pitch like Adelaide, the strip has tended to play quite flat in recent years, which could make life easier for Shaw. If he gets going he can help India set a strong platform quickly, and ease the burden on the middle order.

Cons: Former India opener and captain Sunil Gavaskar believes Shaw plays too many shots too early and with hard hands. Dissecting his technique further on 7 Cricket, both Gavaskar and former Australia captain Ricky Ponting pointed out the yawning gap Shaw leaves between his bat and pad early against the new ball as well as the lateness of his front foot movement - he is often yet to plant his foot before he plays the ball. These are areas an expert Australia attack could continue to exploit relentlessly.

Time to give Shubman Gill a Test debut?

Shaw's teammate in the Under-19 World Cup two years ago, Gill has been restless to make his Test debut ever since he got a maiden call-up to the squad around a year ago. If Shaw is dropped, Gill can open or bat in the middle order as a replacement for Kohli.

Pros: Gill's biggest strength is his classical technique and preference to play along the ground. Coaches who have worked with him point out that Gill has that extra time to play his shots, which is a key strength on fast and bouncy pitches. He also has a quiet temperament. Gill has tall first-class scores playing for India A overseas and at home including double centuries in the West Indies and New Zealand. Gill got good starts in the second warm-up match in Sydney against Australia A, scoring 43 and 65.

Cons: Having started on a low note, will India be taking a risk by blooding an inexperienced batsman against a ruthless opponent at one of the most daunting cauldrons in cricket?

Can KL Rahul take Kohli's spot?

Rahul is the most experienced batsman among the reserves to take the middle-order slot at No. 6 if Rahane and Hanuma Vihari move one spot higher than their regular positions in Kohli's absence. A confidence player, Rahul came to Australia wearing the Orange Cap for the most runs this IPL season, which was played in the UAE.

Pros: He knows Australian conditions and bowlers very well with this being his third tour. In 2014-15, he stroked a wonderful 110 in Sydney.

Cons: The lack of first-class cricket. Rahul did not play in any of the two warm-up matches in Sydney, and his last Test was on the 2019 tour of the West Indies where he struggled to provide starts as an opener. He was subsequently dropped from the home Test series against South Africa and Bangladesh and not included for the two-Test series in New Zealand in February. Rahul's struggles an opener have been longstanding. Having failed in England in 2018, he struggled once again in Australia later that year, opening, with a highest of 44 in three Tests.

Should India play five bowlers?

This would mean playing a second spinner in Ravindra Jadeja as an allrounder along with three fast bowlers and R Ashwin as the primary spinner.

Pros: This would reduce the workload of a pace attack that is likely to include one debutant in either Mohammed Siraj or Navdeep Saini. Jadeja can provide plenty of control, as he showed while taking five wickets at the MCG on the 2018 tour, and play a holding role if need be. The other significant advantage of playing Jadeja is his experience and skill with the bat, with an improved defensive game to complement his ability to counterattack. Since the start of 2018, his average of 53.30 in Tests is the second-best among all India batsmen, and in this period he has scored six half-centuries - three of them away from home - and a maiden hundred against West Indies in Rajkot.

Cons: It isn't yet clear whether Jadeja has completely recovered from the hamstring injury that he picked up during the T20I leg of the tour, which ruled him out of the first Test. The other argument against Jadeja would be that a specialist batsman might be the need of India's hour, given how brittle their batting proved during the first Test, and given the absence of Kohli.

Should Pant replace Saha?

While Wriddhiman Saha battled injuries over the last two years, Rishabh Pant grabbed the opportunity with an impish smile, a motor mouth and let's not forget his robust batting. After an eventful debut series in England, which included a fourth-innings hundred in the final Test at the Oval, Pant was an ever-present during India's 2-1 triumph in Australia in 2018-19. He got starts in every innings and finished the tour hammering 159 in Sydney.

Pros: In the absence of Kohli India will need solidity and big runs from at least one batsman in the lower order. Pant's biggest strength is his intent to dominate, which Kohli said was missing when India folded inside an hour in the second innings in Adelaide last Friday. Overlooked in the white-ball segment of this tour, Pant hit a 73-ball 103 in the second innings of the second warm-up match the Indians played under lights.

Cons: Before this tour, Saha was seen as India's first-choice keeper in spin-friendly home conditions, and Pant as the preferred option away from home, where his prowess with the bat was seen as making up for any deficiencies he may have with the big gloves. But though Pant made a hundred in the warm-up game, Saha, who made two ducks and a half-century in those matches, was still preferred in Adelaide, suggesting India might see Pant's glovework as a work-in-progress.

Nagraj Gollapudi is news editor at ESPNcricinfo