It's under a tree. It is competing for sunlight (and losing) as well as getting starved of water and nutrients.

You might try seeding fine fescue in the fall.

Thanks mishmosh. Though why this Spring has this happened unlike others? Like you said I guess, the grass is losing the battle.

When researching creeping red fescue for a dense dry shade are of my lawn I read multiples of comments that the clumping cool season grasses need fall overseeding every few years. That sure could be a tree shadow though, or does water stand there?

Thanks trickyputt for your reply. That larger area around the base of the tree trunk would be a shady area. Plus, it is a lower part of the backyard - definitely an area where there would be standing water.

My Father had a lawn care company come out and look at his lawn. They did find poor drainage, grub infestation, excessive shade areas and tree roots. He will be using them for the season to help bring back his once great lawn.