I'm assuming that unless you live north of the border, summer conditions are in full swing. Those conditions are hard on newly laid sod. Your job is to keep it alive until fall. KBG and CRF are spreading grasses and small areas of brown, like in your pics, will be a distant memory. I wouldn't be too worried.

Hey mishmosh, thanks for the reply! I live in Canada. Some people have been telling me it could be fairy ring or a type of fungus.. what do you think?

I guess it's possible. I guess I just assumed your dog was pissing in that area. the only time I had fairy ring it was much smaller and the inside was dying and the outer ring was darker green. yours just looks darker.