If Shubman Gill is India's next Test captain, who will be his deputy?

With Rohit Sharma and Virat Kohli stepping away from Test cricket, the leadership mantle is up for grabs. Shubman Gill is poised to take over as Test captain, but it comes with a rider - who will be his deputy, a designated vice-captain, captain-in-waiting, or, in Indian cricketing history, a powerless foot-soldier.