Context: in a boxing match, boxer A is fighting against the particularly tough boxer B. Even after having taken a lot of punches, boxer B is still standing. During a break, the trainer of boxer A says:
I think that スイッチ has a metaphorical meaning here. Since it is usually associated with switching things on/off, could it mean something like
a way to stop or
a way to defeat? How would you translate it? My translation attempt:
Even toughness can be stopped in some way. You must totally destroy him, kid...
Thank you for your help!
EDIT: for more context, I can say that boxer B is a 打たれ強い boxer. He's an ex kick-boxer who says that boxing punches are 'light' compared to the kicks you get in kick-boxing. Being not afraid of punches, he advances to get close to his opponent even while being hit. He is an infighter, a boxer who fights at close distante from his opponent. Here's the entire page the sentence is taken from. In this page Boxer B has just got up after being knocked down by Boxer A. For further context, here are the following pages: 28-29 and 30-31. The manga is called リクドウ.