"I make no promises. What my endeavour is to see a happy Indian team playing cricket," Shastri told the CNN-IBN news channel from Singapore where he is working as a TV expert for the World Cup.
"Watching India playing in the last three to four months just gave me the impression that they were doing a 9-5 desk job with huge weight and expectations on their shoulders.
"What I want to tell them is that this is sport and they should go out there and enjoy it. And if you lose in that fashion then I am ready to take it on the chin.
"So, no promises whatsoever. I just want India to play happy and good cricket. And you guys watching should enjoy it too."
Shastri, a former Test star-turned-commentator will serve as the team's manager for a tour of Bangladesh next month after Australian coach Greg Chappell declined to renew his contract.
India, World Cup champions in 1983 and finalists in 2003, were knocked out in the first round of the ongoing tournament in the Caribbean after losing to Bangladesh and Sri Lanka.
Shastri, 44, said his role was confined to the Bangladesh tour to give India's cricket chiefs sufficient time to find Chappell's successor for matches in England and Ireland in July.
"I love challenges," said Shastri. "So, when I was asked whether you will put your hand up, I said yes. I never want to shy away from a challenge...and if I can help, nothing like it."
Shastri said he agreed with Indian cricket officials that a young team should be picked for the Bangladesh tour with an experienced leader in Rahul Dravid in command.
"You have to look at youth in whatever you do, in whatever walk of life at some stage," he said. "There is a shelf period for everything and if you have got to experiment, then do it against Bangladesh.
I am not saying that Bangladesh is weak. They have thrashed South Africa, they have laid India low in this World Cup, so you can never take them lightly.
"(But) there's going to be a lot of cricket to be played by India in the next 12 months, so if you want to give youngsters an opportunity then do it early.
"When you are playing a Test match, you would like to be playing with your strongest side. So, it's not that the seniors are out of it totally but I would like to see youngsters given opportunities and see what happens."
Shastri played down media speculation of a rift in the team between the senior and junior players.
"I have read about it," he said. "When I reach Bangladesh I would try my best to clear everything out if there is a problem. No big deal."
Asked if he was confident of the team's revival, Shastri said: "A good team doesn't become a bad team in two weeks and a bad team doesn't become an excellent one in two weeks. Be patient."
Shastri, a right-hand batsman and left-arm spinner, retired in 1992 after playing 80 Test matches in which he scored 3,830 runs and claimed 151 wickets.
He also made 3,108 runs and took 129 wickets in 150 one-day internationals.
Widely hailed as possessing a sharp cricketing mind, Shastri led India in one Test match, securing victory over the West Indies on an under prepared wicket in Chennai in 1988 where debutant Narendra Hirwani grabbed 16 wickets.