Lost cause?

We had our lawn turfed while we were away last week, they said it would be finished on Friday but actually they finished early. We scrabbled around and got someone to water it for us (I don’t know how much they did, but it was a favour and I was grateful anyone would). We have some very sad looking patches – looks worse in the photos than real life – but in many of the yellow patches there are green shoots). My question is… are these bits lost causes now? And if so what do I do about it?