Hi all, I'm new here and did a quick search on this question but couldn't really get an answer.
I run 2x /week 7 miles total. Pretty fast 6-6:30 miles and have New Balance 766's because I have slight pronation.
This Tuesday I got a new pain in my left foot right in the little indentation between my heel and the long bone along the outside of my foot. Tried running again Thursday and after 3 minutes the pain came back. Rolling in more onto the ball of the foot reduces the symptoms slightly.
I also get pain in the same area if I make a fist with my toes and then point my foot. Only in the left foot, which also hurts when I run, not the right. It's not really in the arch or heel.
Does anyone know what this is and how to treat it?

Even better is there a stretch or exercise to prevent this from happening again?

Thanks