"Hand-eye reaction is not Tendulkar's problem; he probably is better and faster with his hands than he was in 1992. But the one thing that he can't escape from is that the body is naturally slowing down," Crowe, one of New Zealand's finest batsmen who scored 5444 runs in 77 Tests, said.
"Firstly, the back and hamstrings are probably 10 percent less flexible, and his agility and speed down by 10 percent too. Tendulkar will naturally find that he is not as quick as before.
In particular, it is against fast bowling that his feet and body will find it increasingly hard to move quickly enough into position," Crowe wrote in his column for ESPN Cricinfo.
Crowe felt that Tendulkar, who has scored 100 international centuries, won't face any problems whatsoever from the spinners as he is as good as anyone in the world.
"Against spin, he is absolutely fine and as good as anyone in the world. But despite batting brilliantly against Australia's fast men at the start of the year, a pattern began to emerge as to his dismissals: playing on, lbw, cleaned bowled.
"Now, nine months on, every team's analyst will tell every fast-bowling attack that, as New Zealand showed in recent weeks, anything over 135km pitched up full and his feet and body won't respond quickly or for long enough, anymore," Crowe cautioned. More