So, in Brazil we constantly hear about how Filipe (OH) and Serginho (L), both from Sada Cruzeiro, never made the adult NT despite being two of the best athletes in our league for years. Personally, I'd also add Bob Dvoranen (OH) from Minas, who's like a second Dante.
This got me thinking: has there ever been other cases in other countries?
ETA: I mean both male and female players, just to make it clear.