India captain Shubman Gill, who has not trained due to a neck spasm sustained during the first Test against South Africa, will undergo a fitness test on Friday in a last-ditch attempt to be available for the second game, batting coach Sitanshu Kotak has indicated.

Gill developed the spasm on the second day of the opening Test and hasn't returned to the nets since. While his chances remain slim, the BCCI sports science team is waiting as long as possible before taking a final call. The second and final Test begins on Saturday.

The development could also impact his selection in the ODI squad for the three matches against South Africa starting on November 30. The squad for that series is expected to be picked on November 23.

In Gill’s absence, vice-captain Rishabh Pant is likely to lead Team India, marking his first-ever Test as captain. Pant has not captained any international Test match so far.

"See, he is definitely recovering really well, because I also met him yesterday," Kotak said ahead of a practice session that Gill skipped.

"Now, the decision will be taken tomorrow evening, because the physios and doctors have to decide whether, even if he is fully recovered, there's a chance of the spasm recurring during the match. That is very important."

"If there is a doubt, then I am sure he will rest for one more game because it won't help the team otherwise. A player like Shubman, and he's the captain so any team would miss him," Kotak added.

While acknowledging the impact of Gill's absence, Kotak expressed confidence in the bench strength.

"But if he is missing out because of injury, we have batters and plenty of good players. They are professionals; they should come and perform for the team," Kotak said.

"We all wish he plays, but if he doesn't, we will definitely have a good replacement and maybe the guy coming in will score a hundred."

In the first Test in Kolkata, Dhruv Jurel batted at No. 4 in the second innings, and Kotak did not rule out that option again, though he stressed that combinations would only be discussed after Gill's fitness test.

"Jurel batted at No. 4, so he is one option. But until we know about Shubman, there is no point discussing who will play," he said.

"Once we know, and once we see the wicket tomorrow, we will think about the best combination."

Kotak summed up the significance of Gill's absence in the first Test with pointed clarity.

"In the last game, nobody discussed much about what our chances would have been had Shubman batted in both innings," he said.

"The second innings may not have even mattered. If in the first innings he had batted and we had one partnership, with a 100-run lead, we would have been fine. That's not an excuse, but a reality that he couldn't bat in two innings."