Kevin Garnett is fiercely protective of the Celtics.
According to Paul Pierce, Garnett said he regretted not joining Boston sooner. When Ray Allen left, Garnett led the charge in excommunicating him. Garnett nearly retired rather than accept a trade to the Nets in 2013.
So, how did Garnett feel about Kyrie Irving leaving the Celtics for the Nets last summer?
This type of talk is way overblown. Irving went to New York, the city where the pressure is most mythologized. It's different with Brooklyn, which gets second billing for attention relative to the Knicks. But Irving and Durant definitely elevated the Nets' profile. They are a big deal now. Boston isn't that special. The NBA is full of teams that play in a "tough town." I'm unconvinced the differences between those places really scare off players.
Besides, Irving was exactly the type of player Garnett described. Irving went 7-for-22 in a playoff game, said "I should have shot 30" then went 5-for-16 with no assists in the first half of the next game. He didn't play as much in the second half, because Boston was getting routed.
That was the biggest problem for Irving with the Celtics: They didn't win enough.
Irving contributed to the struggles. But even Danny Ainge said the roster wasn't properly constructed. Boston's problems spread well beyond Irving.
But he bore the brunt of the blame. It's easy to see how that environment would be unappealing to him, especially because he played well enough to draw offers effectively anywhere else he wanted to go.
It had nothing to do with "cojones."