Leach was ruled out of the five-match series on Sunday due to a stress fracture in his back
The white-ball series was originally intended to be played across six venues, including the Indian cities of Jaipur, Visakhapatnam, Cuttack and Thiruvananthapuram, but will now be hosted entirely in Ahmedabad (ODI) and Kolkata (T20).
"The decision ... has been done to mitigate biosecurity risks by cutting down on travel and movement of the teams, match officials, broadcasters, and other stakeholders," BCCI said in a statement.
The two series will be played between Feb 6-20.