We can't determine what's affecting the lawn by viewing the photo.
Perhaps you can use this diagnostic tool to identify the problem:
I think it's Rust. What can I do about it?
You did well to diagnose the problem.
Lawn rust is controlled mostly by cultural practices as noted in this bulletin:
After reading this and other articles, the bottom line is there's not much you can do about it. Yea, you can try to do all these things to a T but .... for the most part it's there to stay is my thoughts. Thanks for your assistance.
Not necessarily there to stay but probably to stay in the short run when conditions are favorable. In the long run the recommended practices can reduce the problem to a rare occurrence.