So far, all information on The Last of Us II focuses on Ellie, deuteragonist of The Last of Us. We don’t know yet on what’s going on with protagonist Joel from the first game though we heard his voice in the first trailer and know he will play a role in some way. What we found out recently is that Ellie is not only the main protagonist, but ala Joel from the first game, she too will be accompanied by an NPC of her own. This new NPC will like be similar to how Ellie herself was in the first game in how she provided assistance to the player such as pointing out enemies, helping kill enemies and such. However, Naughty Dog has actually not revealed who the NPC is; it could be someone from the trailers, someone brand new, or even Joel.

SOURCE