The Ready State Virtual Mobility Coach is like having a virtual Kelly Starrett in your pocket.
If it feels like ripping muscle there’s a good chance it’s ripping muscle so be careful. Maybe just do some smashing on it and work on some dorsiflexion without having a pinned down for a while. See how that feels.
As far as the video that roller is pretty big so it’s probably on the I Keeley’s tendon but also on the soleus