9 Year old boy (wears hockey skates) has a large lump -grape-like on the back of his heel. Feels and looks like a grape under skin. Tender when push?

Sounds like hematoma. Sounds like the kid broke a blood vessel under the skin in this area and has accumulated a blood pocket/hematoma.These are due to localized trauma and may takes weeks to fade.Your doc could confirm this if concerned.There is not much you can do about it.