NFHS Rule 1.6.2 & 3. cites that the Head Coach and CAPTAIN(S) from each team shall attend the prematch conference.
That captain(s) can be any player on the team, dressed in street clothes, wearing a cast on his/her leg, wearing jewelry, etc, etc. That CAPTAIN does NOT have to be the “speaking captain” in sets 1, 2, 3, etc. The visiting CAPTAIN at the prematch is the only captain who will be required to call the toss.
Please see NFHS Casebook page 6; Situation 1.6.3 (B) which addresses this spot on! Thanks