Shastri was appointed Team Director after India lost the fifth and final Test against England in under three days to go down 1-3 in the series. "People can be judgemental, but we have not played a five-Test match series in a long time. When you play five Test matches in 40 days your fitness gets exposed. But if you are inexperienced it comes to the fore.
"My role is to oversee everything. All of them report to me. This is for the ODI series in England," Shastri said.
Asked if his position would affect Fletcher's stature, Shastri said, "Absolutely not. He stays as the head coach. And these two (Sanjay Bangar and B Arun) will be his assistants."
Shastri said he took up this assignment as he wanted to contribute to the team.
"It was an important time in Indian cricket. When asked I thought about it and then said, 'fine'. The state of Indian cricket is such that I know I can contribute. I have never been scared about how tough the job is or how easy the job is. The important thing is the contribution.
"If I am here today, and at times some forget, it is because of the BCCI. The platform they gave me when I was a junior cricketer to play for my state and then the country," he said.
On whether he has had a word with skipper Mahendra Singh Dhoni and Fletcher after his appointment, Shastri said, "I spent about two hours with them (on Tuesday). We had a chat about where things are at the moment, how things have to be addressed, and how important communication will be."
Asked what he felt were the reasons for India's failure in the Test series, Shastri said it was inexperience.
"If you calculate the number of Test matches played by the XI as opposed to some of the tours where we fared worse, here we at least won a Test match."
"We did not win a Test in 1974 (3-0) and were whitewashed on the last tour here with some of the biggest names (in the team). So if you calculate the number of Test caps between this unit and some of the other units that have come (in the past), it is chalk and cheese," he explained.
"On this tour I saw India's greatest ever overseas win I have seen. I know it because I have never seen a track like that and with this kind of inexperienced side for them to pull it off. Then I also saw some spineless cricket over the last three Tests matches."
Shastri said India did not show the fighting spirit in the last two Tests.
"Spineless means stomach for a fight. People would have accepted 3-1 if there was a little more fight. The conditions what you saw here, barring the first Test, every track had serious juice on it. When I evaluate everything I put it down to inexperience. When they come back to England (next time) they would be better players," he said.
"What does experience do? It builds your mental strength - when you are down, you can still recover. But here when you lack the experience and when you get hammered, or you have two or three innings where you don't do well, then you go downhill straight," he added.
Asked what was has been the most disappointing aspect of India's performance so far, Shastri said, "My only disappointment was players at times making the same mistake. That disappointed me. Everyone makes a mistake, but you want to try something different.
"Like [Alastair] Cook. He changed his stance, stood a foot outside the crease. You need to try something different instead of getting out the same way."
The former captain justified the critical columns he wrote before his appointment.
"I was hard on (Cheteshwar) Pujara and (Virat) Kohli specifically because they came here with big reputations. And they have been brought down to earth with their techniques being found out against the moving ball. And there is nothing wrong in that, it has happened to the biggest players," he said.
Shastri was appointed Team Director after India lost the fifth and final Test against England in under three days to go down 1-3 in the series.
"People can be judgemental, but we have not played a five-Test match series in a long time. When you play five Test matches in 40 days your fitness gets exposed. But if you are inexperienced it comes to the fore.