India's cricket greats have begun talking about a topic that was considered unthinkable a year ago -- Sachin Tendulkar's retirement from the sport. Or, at least, the need for the record-breaking batsman to quit one-day cricket to prolong his Test career, like former Australian captain Ricky Ponting did this week.

"Maybe his time has come," former World Cup-winning captain Kapil Dev told a news channel. "Every player has his time. Age is not on his side as it was earlier." Tendulkar, who turns 39 in April, is not only the world's leading batsman in both the Test and one-day formats, but also the longest-serving international cricketer, having made his debut in 1989.

Fans have been left on tenterhooks as Tendulkar, who has scored a record 51 Test and 48 one-day centuries, struggles to reach the unprecedented milestone of 100 international hundreds. Tendulkar has now gone 11 Tests and nine one-day internationals (ODIs) without a century since making 111 against South Africa in the World Cup in March last year.

It is the longest gap for the prolific batsman without a three-figure knock, even though scores of 85, 91, 94 and 80 in the interim suggest his form has not deserted him. The immediate spark for talk of Tendulkar quitting is his indifferent run in the ongoing tri-series in Australia where he has managed just 90 runs in five games at an average of 18.

Former captain Sourav Ganguly, who played alongside Tendulkar from 1992 to 2008, said his ex-teammate's decision to pick and choose one-day matches was costing India dear. "Sachin has to ask himself whether it's helping him as a one-day player or if it's helping the Indian team," Ganguly told the news channel. "If Sachin can't get an answer to these questions, he has to go."

Tendulkar, who has played a record 458 one-day internationals, has turned out in just 18 ODI matches in the past two years, including nine in India's triumphant World Cup campaign in February-April 2011. He still managed to record the first ever double-century in ODIs -- 200 not out against South Africa in February 2010 and was the star performer in India's World Cup win with 482 runs, second only to Sri Lankan Tillakaratne Dilshan's 500.

"It affects everyone's form if Tendulkar keeps coming in and going out of one-day tournaments," Ganguly said. "I said after the World Cup that Sachin needed to look at his one-day career because he had achieved everything in one-day cricket." Ganguly dismissed batting legend Sunil Gavaskar's suggestion that the selectors should talk to Tendulkar about his one-day future.

"I don't see any of the selectors stepping in," Ganguly said. "They are not going to stand in front of Sachin Tendulkar and say 'Listen little champ, you need to go'. That is never going to happen." A national daily urged former players to lay off Tendulkar, saying the decision to quit or not should be left to him.

"A lot has been said -- especially by former sportspersons who themselves stayed on well beyond their use-by date -- about Tendulkar's ODI career," the paper wrote. "Whatever the intentions, these gems of seemingly timely advice are clearly uncalled for. Sachin has served the country with exceptional pride and genius for far too long and he deserves the right to choose his own time of departure." In the immediate term, Tendulkar has two games -- against Australia on Sunday and Sri Lanka next Tuesday -- and a possible best-of-three-finals if India qualify, to silence his critics.