Do I need SAT Subject Tests for UVA?

Hi, I plan on applying to UVA regular decision, and I will be taking the SAT subject math 2 and biology tests coming up on november 7. I really can’t gauge how I’ll do, and I know UVA recommends subject tests. If I was to not submit them, how poorly would this reflect on my application?

Please read the testing section of the instructions for our official stance: http://admission.virginia.edu/admission/testing