When David Blatt heard that Kyrie Irving had demanded a trade, he thought back to a conversation with his former star after taking the Cavaliers’ coaching job in the summer of 2014. Blatt accepted the post shortly before the grand return of LeBron James. Irving, on the other hand, had just played through three trying seasons as the young star of the then-moribund Cavaliers. He had a simple wish. “I can still remember Kyrie telling me, ‘I want to come to the game and be happy, and I don’t feel that way,’ ” Blatt said last week, relating that old conversation. “It tells you the importance of feeling this way to Ky. He wants to be happy, and I think that’s working for him now.” Blatt is once again preparing to go deep into the EuroLeague season, with his Turkish team, Darussafaka Dogus, holding a healthy lead on the field in Group A of the EuroCup standings. But nothing could have shaken Blatt’s attention like July’s news of Irving’s trade demand. Blatt was moved by Irving’s nerve. “The first thing that hit me about it was that Kyrie made a very profound statement about himself when he requested a trade,” Blatt said. “It’s a situation that hasn’t been easily interpreted by everyone. It was brave, and it’s one of those things that makes him a special kid.” Most interpretations have targeted the relationship between Irving and James, the four-time NBA MVP who casts the broadest shadow in basketball. It’s an issue Irving refuses to discuss publicly, and one that James, most recently, probably goosed by referring to Irving as his little brother.