A few former India players, including VVS Laxman and Ajit Agarkar, recently raised questions about Dhoni's T20I future, creating quite a storm in the country's cricketing circles.
"People should look back at their career before commenting on Dhoni. The captain has a lot of cricket left in him and it is the duty of the team to back the legend," Shastri said.
Shastri was having a look at the bat autographed by the 2011 World Cup winning Indian team at the Fanattic Sports Museum.
The coach further said the culture of the current team is based on performance and quality.
"There is no one better than Dhoni on the field given his ability behind the wicket and with the bat and his presence of mind and sharpness on the field."
Shastri lauded the players' athleticism and said: "In terms of fielding this team is the very best in the world at the moment and that's something that separates this team from Indian teams of the past."
India will take on Sri Lanka in three Tests beginning with the Eden five-dayer on November 16, and this will be Shastri's first home Test series.
"This team always turns up on the park to win. We hope to win the series spread over one and half months before going to South Africa."
Hardik Pandya has been rested for the series and Shastri said: "This team is not about one particular individual, we lose together, we win together."
Earlier, accompanied by bowling coach Bharat Arun, Shastri spent about two hours admiring the Fanattic Sports Museum curated and set up by sports historian Boria Majumdar.
While taking a stance with Sir Donald Bradman's bat from 1948, the former all-rounder said: "The quality of wood is such you can still play a few shots with it."
He compared Virat Kohli's bat with Sir Don's and donated his 2015 World Cup team directors' jersey and cap to the museum collection, and was particularly impressed with the Usain Bolt memorabilia.
Picking Bolt and Mohammed Ali as two of his personal favourites, Shastri said: "Every Indian cricketer should make a trip to the museum and enjoy the collection."
Arun, too, was impressed and said: "I would love youngsters training at the NCA to come to a place like this and absorb in cricket history."
First Published: November 14, 2017, 4:55 PM IST