While you can play through Days Gone without bothering to upgrade your health, stamina, or focus, increasing them makes the game much more comfortable to experience. To do that, you need to find the NERO Injectors scattered across the map. Each of these increases one of your bars by 25, up to a maximum of 350 health, stamina, and focus if you grab them all.
And let me tell you, taking down hordes and clearing endgame fights is much more enjoyable if you've gathered a few NERO Injectors to buff yourself along the way. So, here's where to grab them all.
