Late season rust - what to do?

I have several areas of rust developing in my lawn. My lawn is a new this year bewitched reno. There's been lots of rust going on in my town this year, but It's so late in the year I'm really surprised that I have this problem now. I sprayed seranade a couple times on the reno area as a preventative measure and did another app of seranade last week when I first noticed the rust start to develop. I know urea is often used to help get the lawn to grow out the fungus, but it's so late in the year and top growth has slowed to a crawl and should be just about done in the next 10 days to 2 weeks or so, so I'm not sure it would be advisable to do a urea app this late. But the rust is there and has spread a bit from when I first noticed it. I'm worried being it's a monostand and can be more prone to fungal issues that I'll get damage if I just leave it. I'm wondering if I do just leave it alone if I'll get over winter damage. Looking for some advice on what my best course of action would be.