Maybe the basketball? Hope it goes away.
Ooh. I had that for years and years, finally got rid of it by icing it into submission. Lots and lots of icing.
Yes, I had it on my left one for decades, and finally ice it into submission. It was scary to feel it on the right side, but it was only for an hour or so in the middle of one night. For whatever reason, that time of night (3am-ish) is a time when a lot of leg pains appear for me, e.g., shins, outsides of my thighs. In any case, no soreness in the right Achilles since, so hopefully it was just a one time happening.