Bangar believes that India should tweak their winning opening combination and should give a chance to Mayank Agarwal alongside Shikhar Dhawan.
Shastri was appointed India chief coach in 2017 after Anil Kumble's tenure ended prematurely in controversial circumstances.
The general belief is that the bowling unit under coach Bharat Arun did exceptionally well in the last year and a half while the team's fielding under R. Sridhar has also improved a lot
Dhawan injured his hand during the team's 36-run victory against Australia on Sunday and remains a doubt for the rest of the 50-over tournament.
The contracts for all these appointments begin from Tuesday and are effective until the end of the 2019 World Cup.