All of them have attended a special training camp for eight days in Bengaluru in the last week of July.
The 59-year-old Shastri's contract comes to an end after the completion of T20 World Cup in the United Arab Emirates in October-November.
Prasad, who was the chief selector until last year, said the sectors would look for consistent performers in the team and keep them on standby and ready to replace those on the wane in the national te
While the selection of a number of youngsters in the squad is on expected lines, many of them impressed in the suspended IPL and have been rewarded with their maiden India call-up.
Natarajan suffered a shoulder injury as well as a knee niggle that had ruled him out of the first couple of games of the five-match series.
Virat Kohli said he respects Anil Kumble's decision to quit as coach and that there is highest regard for him as a player.
Dravid said that time has come to also decide on the spin combination with finger spinners Ashwin and Jadeja.
The four top-ranked Test teams: India, Pakistan, Australia and England are separated from each other only by 10 points.