They shouldnt be worrying about it at all since it would be the healers job to do so.
It’s a team game. Relying on your teammates is literally the entire point of it.
If tanks want to play solo, there will be delves… or they can go play a single player game.
You all need to come to terms with failure being an option. In fact you SHOULD be failing more than succeeding. If not then there is no point to the challenge.
Wow is a video game.