The powerhouses of the modern game are about to collide in Brisbane and Ahmedabad and there will surely be some fireworks along the way. But will there also be some long goodbyes?

We will be intrigued by three players, who share 510 Test caps, 41,520 Test runs and 113 years between them: Sachin Tendulkar, Ricky Ponting and Jacques Kallis. But will we be marvelling at their immortality or wincing as they vainly seek to recapture the magic of their earlier years? It could be enthralling; it could be very painful.

Tendulkar and Ponting are now accustomed to queries about their future but somehow retirement has not been an issue with Kallis recently. It may be that his recent form has been so impressive; it can't just be that the new batch of hair upon Kallis's head creates an impression of youthfulness, which deflects any interrogators.

Both Tendulkar and Ponting have insisted that they are pragmatists. "I am 39," said Tendulkar recently, "and I don't think I have plenty of cricket left in me. But it depends on my frame of mind and my physical ability. As long as I feel I can deliver I will continue playing".

Ponting, in conversation with Ian Chappell last week, explained what keeps him going: "It's the thrill of the contest." But he added: "I'm a realist and I'll understand if there are players out there who can play better than me. I'll be the first to walk away. I'm not going to let it get to the stage where the selectors drop me. I think I'll identify the right time."

The great players always say that. They think they know the best time to go but they are not always right. Very often the worst judge of a cricketer's worth is the cricketer himself, especially if he is a really high achiever.

This should not surprise us. One component of the great sportsman is a deep reservoir of self-belief that insists that he can prevail whatever the circumstances, whatever the odds – and whatever his age. The best are seldom defeated because of their own frailties. External factors intervene: a little stone on the pitch causing the ball to deviate freakishly, a spectator in front of the sightscreen at the critical moment and, on one occasion, according to Brian Close many years ago, the 12th man's inability to deliver the correct flavour of chewing gum.

Anyone with that innate self-belief is most unlikely to reach the conclusion that the powers are on the wane. That would contradict the thought processes of two decades. Hence Tendulkar and Ponting are not guaranteed to be the best judges of when to go. They need good, strong men/women around them. They may well have them.

We know that Ponting has a chairman of selectors of vast cricketing wisdom and experience in John Inverarity. Ponting, it is true, will never be dropped. His standing in Australia does not allow that. But this does not mean that when the time comes Inverarity will shy from his duty to have a word, directing one of Australia's greatest to go gracefully.

The South Africans will seek to hasten this process this week. Their first weapon will be pace – and they have some in the shape of Morne Morkel and Dale Steyn. Ponting is 37. His ability to pull fast bowling was awesome from the moment he first turned up at the Australian academy as a teenager. Rodney Marsh has recalled how a little audience would assemble for lunchtime sessions in the indoor school where he would ratchet up the bowling machine and Ponting, to general consternation, would keep pulling.

But the eyes and the reflexes start to go sometime. Likewise the Australians, aware of his frailty against the early yorker, will check out Kallis's reactions to their fastest bowling. They know he has a sublime technique but what about those 37-year-old eyes?

In India there is always unfettered adulation whenever Tendulkar comes to the crease. But if England can undermine him then there will be torment in the subcontinent.

Tendulkar, in his 23rd year as a Test cricketer, is deified in India and it is tough to drop a deity. He has just hit a hundred against the Railways in a rare outing for Mumbai but there are no real gods in cricket and he could yet become a source of angst for the home side if the Test runs dry up in his 40th year.

England will go hard at him and at Virender Sehwag as well. Sehwag is 34, not necessarily MS Dhoni's bosom pal, and he has not hit a Test century for two years. Once again there will be a determination to test those reflexes. For the first time the arrival of Tendulkar and Sehwag at the crease may provide an opportunity for India's opponents rather than a source of extreme apprehension. Or this pair may still be capable of flirting with immortality. Either way it will be interesting.