Ravichandran Ashwin has withdrawn from the third Test with England due to a family medical emergency, as confirmed by BCCI Secretary Jay Amit Shah.
Ashwin may also miss the 4th and 5th Tests.
With Ashwin absent from the Rajkot Test, India is forced to field only 10 players and four specialist bowlers.
MCC rules allow a substitute fielder if a player is injured or ill during the match, with certain restrictions.
Ashwin's departure, not due to injury or illness in the ongoing game, permits a substitute fielder with Ben Stokes' consent.
A complete replacement is usually allowed for a player ruled out due to on-field concussion.
Despite other injuries, India can't select a replacement.
However, a formal request to England and Stokes' agreement could allow Ashwin to be replaced by Washington Sundar or Axar Patel, both capable with bat and ball in the second innings.