India's final mile on the road to the World Test Championship (WTC) final - successive series wins in Australia and against England at home - has featured contributions from unlikely heroes that rescued the team from tricky situations. But most of them might not even feature in the WTC final against New Zealand if India carry a full-strength squad. ESPNcricinfo looks back at six of them and where they stand.
Mohammed Siraj
Mohammed Siraj picked up two wickets in the first two sessions of the fourth Test
Where was he? Part of the Test squad in Australia only because of an injury to Ishant Sharma.
Opportunity: Further injury to Mohammed Shami during the Adelaide Test in Australia, which pushed Siraj for a debut in Melbourne.
Contribution: With 16 wickets in his first five matches, Siraj has carried his stellar run with the red ball to the highest level against quality oppositions. On debut in Melbourne, he first foxed a set Marnus Labuschagne with the leg-side trap before setting up Cameron Green with outswingers only to pin him in front with one that came in. He carried forward that success into the series decider in Brisbane, where he bagged his maiden five-for and set up a memorable win. In the fourth Test against England in Ahmedabad, Siraj got rid of Joe Root and Jonny Bairstow at a crucial stage in the first innings, as India went on to wrap up the series.
Chances of playing the WTC final: Only if one out of Sharma, Jasprit Bumrah and Shami is injured.
Axar Patel
Sanjay Manjrekar and Ian Bell on Axar Patel's dream debut series
Where was he? Part of the Test squad for the England series but because Ravindra Jadeja was out injured.
Opportunity: Made his Test debut in the second Test in Chennai after missing the first match due to a last-minute injury.
Contribution: Patel has burst on to the Test scene and achieved immediate success as a like-for-like replacement for Jadeja. He replaced Shahbaz Nadeem from India's loss in the first Test against England and pocketed 27 wickets in three games at a staggering average of 10.59. His first Test wicket was Root, who top-edged a sweep to short fine leg while trying to play against the turn. Patel even grabbed three consecutive five-fors across the second and the third Tests and added a fourth to the list in the next game, as England struggled to find answers to him. He also contributed with 43 in a crucial century stand with Washington Sundar to extend India's lead in the last Test.
Chance of playing the WTC final: Only if Jadeja is unfit and Hardik Pandya doesn't bowl, and India want to play five bowlers.
Washington Sundar
Sanjay Manjrekar believes the sky is the limit for Sundar, whose 96 put India in pole position
Where was he? Travelled to Australia as a spare bowler due to enlarged squads during Covid-19.
Opportunity: R Ashwin was out with an injury in Australia after the third Test, and Kuldeep Yadav's inclusion would have made the tail longer, which led to Sundar's Test debut in Brisbane.
Contribution: Sundar's major contributions have come with the bat in his four Tests so far. He has three half-centuries in just six innings, including two match-defining knocks of 62 on debut in Brisbane and 96 not out in Ahmedabad. While the former brought India's innings back on track in a 123-run stand with Shardul Thakur, the latter ensured India built a solid lead after being in a dicey situation. But that doesn't take away his efforts with the ball: he removed a stable Steven Smith as his first Test wicket to finish with 3 for 89.
Chance of playing the WTC final: Very low unless there are multiple injuries because he is behind Ashwin, Jadeja and Patel in the spinners' queue.
T Natarajan
Where was he? Picked as a net bowler for Australia tour after his success in the IPL.
Opportunity: Handed ODI and T20I debuts after Varun Chakravarthy and Navdeep Saini were ruled out with injuries, and Test debut after none of India's first-choice quartet of Sharma, Bumrah, Shami and Yadav was available.
Contribution: Though Natarajan has played just one Test, he delivered instantly in Brisbane by breaking open the match on the first day with the twin wickets of Labuschagne and Matthew Wade who had put on a century partnership. Natarajan brings the left-armer's angle into play, something India have been missing since Zaheer Khan retired. He also has an accurate yorker, aside from variations of slow cutters and low full tosses dipping onto the batsmen.
Chance of playing the WTC final: Almost impossible given India already have a string of pace bowlers who are ahead of him.
Shardul Thakur
Where was he? Much like Sundar and Natarajan, Thakur stayed back as a net bowler for the Tests in Australia.
Opportunity: Drafted in for the Brisbane Test as India struggled to put together an XI following a long injury list.
Contribution: Thakur answered the call with both bat and ball in what was just his second Test - he had limped off on debut against West Indies in 2018 - as India made history. He struck with his first ball back on the way to three first-innings wickets before contributing with a fighting 67 to limit Australia's lead. Not just that, when the hosts threatened to post a hefty total in the second innings, Thakur returned figures of 4 for 61 by rocking Australia's lower-middle order.
Chance of playing the WTC final: Like Natarajan, almost impossible.
Hanuma Vihari
Where was he? Part of the Test squad in Australia, but he has so far played only overseas Tests.
Opportunity: Played the first three Tests in Australia before getting ruled out of the fourth due to injury.
Contribution: Vihari's valiant vigil in Sydney in the company of Ashwin went a long way in India securing a draw, and in turn also booking a place in the WTC final. He had tweaked his right hamstring early in India's second innings and had only Ashwin and the tail for company, as he showed courage to battle against Australia's bowlers. Vihari's innings of 93 in North Sound, and 111 and 53 not out in Kingston in 2019 helped India gain an early advantage in the WTC table on the way to a 2-0 sweep of West Indies.
Chance of playing the WTC final: Little chance if India stick to playing five bowlers, but may get the nod at No. 6 or 7 if they decide to play an extra batsman.