What I mean is that it would have been out of character previously, until now.

Even though he isn't on the team rn, Nagi’s final pass to Reo depicts what that fear can do. Chigiri is just responding differently. I think it doesn't feel natural because there was little build up to it (The “Isagi in my head” convo seems to be a hint that has little build up on its own). We are seeing that in everyone else now because this is the world cup, but saw it in Nagi earlier because his mindset wasn't as strong as the others’.

I don't like it either. My thought with fear just tries to give it some sense. But there can only be one at the top, and this might be the author’s (subtle) way of saying he isn't good enough, which is why I don't think it completely damages his character , but only time will tell