But time heals all wounds. And so does winning. Lots of winning.
Perkins proved to be a solid addition, becoming a key defensive cog during two straight deep playoff runs. By most, the trade is now viewed as a win for the Thunder.
Green is still remembered in OKC. He'll likely get a standing ovation when his name is announced on Sunday.
But his on-court impact, while not forgotten, has inadvertently shifted to the back of most fans' memories.
“I hope he's not (been forgotten),” Gibson said. “But I kind of think he somehow is. Because when he was here, I don't think everyone had embraced the Thunder like they do now … I honestly was more upset about that trade than the Harden trade.”
So much has happened since Green last played a basketball game in OKC.
The Thunder franchise, and its fans, have clearly moved on. And so has Green, fully recovered from a scary heart condition (which forced him to miss last season) and finally comfortable in Boston's offense, averaging 11.1 points and 3.5 rebounds.
But for at least a brief moment on Sunday, when his name is called or he showcases his patented athleticism on a smooth dribble-drive, fans and former players alike will briefly remember what he used to mean to this franchise.
“He was really like my brother,” Kevin Durant said earlier this year. “We came in the same year. We've been through everything. The trade was tough for us, but in this league anything can happen and we've moved past it, but he's still one of my best friends. He's a guy that's going to be that way forever.”