"He is just hitting the peak," Gavaskar said of the 31-year-old Tendulkar who begins his 16th season in world cricket this week with the Asia Cup Limited Overs tournament in Sri Lanka.
"I think a lot of batsmen get to that peak between the age of 28 and 33-34. They are really at their peak in terms of just about everything - physical conditioning, mental strength and focus.
"Sachin's best has yet to come and I wont be surprised if his 35th hundred in Test cricket is a triple or bigger than that," Gavaskar told the Sunday edition of Mumbai's Mid Day newspaper.
Tendulkar, who made his Test debut during the 1989-90 season, has scored 9,470 runs from 114 Tests with 33 centuries - just one short of Gavaskar's world record tally of 34 hundreds.
Only four batsmen have scored more Test runs: the retired 10,000-plus trio of Allan Border, Steve Waugh and Gavaskar and current West Indian captain Brian Lara who has made 9,830 runs.
Tendulkar is also the most successful batsman in One-day history with a record 13,134 runs from 333 matches with 37 centuries.
The combined Test and One-day tally of 22,604 runs and 70 centuries makes Tendulkar the most prolific run-scorer of all time.
Gavaskar, the first batsman to scale the 10,000-run Test peak, said the hard grind of 15 years at the top had not taken its toll on Tendulkar.
"He started early, earlier than most," Gavaskar said. "But he has handled pressure well and the physical conditioning that the current team has been put through is certainly helping people to prolong their careers.
"Sachin is a teenager as far as Test cricket is concerned."
Many regard the present Indian batting line-up of Tendulkar, Rahul Dravid, Virender Sehwag, Venkatsai Laxman and skipper Sourav Ganguly as the country's best ever, but Gavaskar refused to be drawn in comparing them with the past.
"It is very subjective and I have never believed in comparisons," he said. "But this Indian team is special because it has not lost the last couple of series overseas."
India drew 1-1 against world champions Australia in January and then won a Test series for the first time in Pakistan in April.
"Beating Pakistan in Pakistan in Test and One-day cricket was a big kick, it was a real, real high for me because we never did it," Gavaskar said.
"I get a big kick out of India's victories anywhere and particularly where we as a team had not been able to do it."
Gavaskar, who played Test cricket between 1971 and 1987 and turned 55 on Saturday, said the big change from the past was the emphasis on physical fitness these days.
"Thats been the one change," he said. "Otherwise, the game is basically the same. There is emphasis on physical fitness because of the proliferation of the One-day game which requires peak fitness and lots of energy levels.
"This is not to say that there was no fitness in the past and I am not even referring to my generation. They got triple hundreds and they bowled 30-40 overs a day. You had to be fit to do that.
"It's just that the preparation for international matches have changed considerably."