Hi
I had a similar problem last indoor season. pain was slowly getting worst and when i rested it healed slower than expected. I did A LOT of plyo that winter (even barefoot). There was no irritation or anything that would lead me to soft tissue. Also moving the bones was not painful (except under load liek running etc) I had an x-ray and nothing showed up. Than I went to some other doctor and he sain it might be and early sign of stress fracture and that I should rest. That scared the shit out of me so I took a month (5 weeks or so) off. After that i never felt this pain again. I still do very limited volume of plyo and make sure my shoes are in good condition.