How Can Achilles Heel Discomfort Due To Stretching Be Treated?

I've had a reoccurring issue with my achillies for about a month now. Some history, I ride a bike everywhere, play hockey and for about a month I've developed an issue with my achillies where there is no pain, yet it feels like a rubber band stretching inside my foot...it goes away every night, and comes back about mid-day every day. I'm going to physical therapy to attempt to get it fixed, but it seems like nothing i'm trying is helping, what is going on!