We'd really need photos to be sure. They're best taken in shadow or, better, on a cloudy day to reduce the contrast in the lawn. We're looking for a closeup of the problem area, and also a more distant shot to see the context of the issue.

While awaiting the photos:

By “spun out”, do you mean the grass looks like the blades have been subjected to spinning in a clothes dryer?

I do realize that this may be a regional expression, one not familiar to those living in this part of the country.

Spun out is not used anywhere I've lived.

What kind of grass, and where do you live?