Sachin Tendulkar admitted on Friday that he is contemplating retirement and said he would reassess his future next month.
In an interview to be broadcast on Indian television on Friday, the 39-year-old said he would decide on a "series by series" basis as he acknowledged that the clock was running down on his record-breaking career.
"I am 39 and I don't think I have plenty of cricket left in me," he said to a TV channel.
Asked if he has been thinking of retirement, he replied, "Of course, I have been.
"I am 39 plus and it is not abnormal for me to think of it. At that moment, I will go by what my heart says. At this moment, my heart says I am okay. But you will have to look at series by series."
Any talk of dropping Tendulkar -- the highest run-scorer in Tests and the first player to score 100 international centuries -- had been taboo in India.
But some commentators said last month it was time for him to hang up his bat after he made a series of low scores against New Zealand in a home Test series.
Tendulkar has scored a record 51 Test centuries but he has now gone 25 innings without a hundred in the five-day format since making 146 against South Africa in Cape Town in January, 2011.
England are to play four Tests against India in November and December and Tendulkar made clear he expected to be playing.
"I need not take a (retirement) call right now. When I play in November, I will reassess things," he said.
Questioned about suggestions from a number of former players that his reflexes had slowed, Tendulkar insisted that only he could determine whether he was still up to playing at the highest level.
"I am still the best judge of what happens to my mind and body. When I feel it is time, I will take a call," he said.
"It is going to be a tough call nevertheless. It is going to be tough because this is what I have been doing all my life. It is going to be difficult to suddenly hang (up) my boots one day."