Kumble, with 607 wickets in 126 Tests, looks a doubtful starter after failing to recover from a groin strain suffered during the drawn opening Test in Chennai on Sunday.
"We still have not decided on the team combination because there are a couple of injury concerns. I am feeling better, but we'll wait till tomorrow morning," Kumble told reporters here on Wednesday.
India desperately need a fit Kumble as their bowling options are already restricted following finger and toe injuries to teenage paceman Ishant Sharma, who was the find of the recent Australia tour.
Sharma is in contention for a place here after missing the first Test, but his captain said medical staff still needed time to assess his condition before making a final decision.
"We'll just have to wait. We'll take a final call tomorrow morning," said Kumble, the third-highest wicket-taker in Tests after Sri Lankan off-spinner Muttiah Muralitharan and retired Australian leg-spinner Shane Warne.
"Whatever combination we will have, I think we have enough quality to do the job. We have worked out some plans to ensure we put pressure on South Africa and get the right result."
The fitness problems have come at a tricky time for India, already struggling to find match-winning bowlers against South Africa. Their bowlers toiled in Chennai as the visitors racked up scores of 540 and 331-5 on a docile pitch.
The hosts are also without record-breaking batsman Sachin Tendulkar, who is ruled out of the match after aggravating a groin injury in the first Test and makes way for Mohammad Kaif.
Venkatsai Laxman, who batted at number six in the first Test, is expected to replace Tendulkar in the number-four slot.
The Indian captain said they were not worried over South Africa's plans to counter opener Virender Sehwag with short-pitched deliveries following the batsman's fastest recorded triple-century in the previous Test.
"I think he (Sehwag) is a good enough batsman to handle that. He has scored 319 in the last innings. He is capable of handling whatever comes his way," said Kumble.
South Africa coach Micky Arthur said Tuesday his team planned to target the Indian opener with short-pitched balls in order to curb his strokeplay.
Visiting captain Graeme Smith said it was one of the options.
"I think as a team it is important to come up with a plan. We have this option of bowling short to him (Sehwag). We have a few things to work on. Hopefully, we execute them over the next five days," said Smith.
He said South Africa were likely to be unchanged after an impressive performance in Chennai.
"I think India have a few more things to think about than us after the last game. If he (Kumble) does not play, they will lose a very competitive cricketer. He is an experienced campaigner and a fierce competitor," he said.
"We have to focus on our game plan. As long as we can get our combination right, I am very comfortable. The pitch looks different here and we are hoping for a result."
The third and final Test begins in Kanpur on April 11.