Returning captain Virat Kohli says he has nothing to prove as India go in search of a historic Test series victory over South Africa at Newlands.

Kohli will return to lead the tourists for the decider in Cape Town on Tuesday after missing a seven-wicket defeat at the Wanderers last week due to back spasms.

Hanuma Vihari would appear to be the most likely batter to step aside for the fit-again skipper in Cape Town, where India have never beaten the Proteas in five attempts in the longest format and must end that record to secure a first Test series win in South Africa.

Kohli's last Test century came against Bangladesh back in November 2019, but the 33-year-old feels the increased scrutiny on him is due to the incredible exploits that have established him as one of the best players in the world.

"It's not the first time [his form has been called into question]," Kohli said. "It's happened a few times in my career - England 2014 was one of those phases. 

"But the thing is, I don't look at myself from the lens that the outside world looks at me with, and eventually the standards that we're talking about today, that I'm being compared with, have been set by myself, and more than anyone else, I take a lot of pride in wanting to do the best thing for the team that I can, and wanting to perform regularly for the team, and hence I've been able to do that for a long period of time.

"You have to understand, in sport sometimes, things do not go the way you want them to go, but at the end of the day I realise, as a player, as a batsman, that I've been involved in very important moments for the team over the last calendar year or so, and for me that is a matter of a lot of pride, that I have been part of very important partnerships when the team needed me, and eventually those moments have been crucial for us in many Test matches.

"So sometimes your focal point has to shift; if all the time you're going to look at yourself and judge yourself on the basis of numbers and milestones, I don't think you'll ever be content or happy with what you're doing. 

"I take a lot of pride and happiness in the process that I'm following, and I'm at peace with how I'm playing and what I'm being able to do for the team when there is a tricky scenario, and as long as I'm doing that, and taking a lot of pride and motivation to be in those moments. 

"I have nothing else to worry about, because the reality of the situation is that you eventually want to make impact performances for the team, and my best effort is always to do that, and I truly believe that I don't need to prove anything to anyone.

"It's just that when you're in the place where I am, you are going to be constantly judged, and that is the job of the outside world. I don't look at myself like that."

Half-century for Proteas paceman Rabada 

Rabada will play his 50th Test at a ground where South Africa have only lost once in the longest format - against England two years ago - since the start of 2015.

Captain Dean Elgar, man of the match in the second Test after making a brilliant unbeaten 96 as South Africa chased down 240 to level the series at 1-1, revealed Rabada needed a "rocket" to fire him up following a loss in the first Test.

Rabada responded by taking three wickets in both innings in Johannesburg and Elgar will expect him to fire again with the pressure on in the final Test.

India ponder Siraj replacement

The tourists will be without Mohammed Siraj after he suffered a hamstring injury in the second Test, so either Ishant Sharma or Umesh Yadav are set to get the nod but Kohli kept his cards close to his chest on the eve of the match.

He said: "We are yet to sit down - myself, the head coach, the vice-captain - to decide what we want to do about [Siraj's] replacement.

"I say that because of our bench strength. It's difficult for us to figure out who will play because everyone is at the top of their game, bowling well, batting well, and these things become a point of discussion, contention, and you have to obviously have a healthy discussion around a decision like that, and just agree that everyone feels balanced about it.

"So yeah, we're yet to have that discussion, but I would rather be in this position where we are yet to decide who's going to play rather than having to figure out other options in terms of managing our balance and stuff like that."