Sources close to the situation in Golden State have informed TMZ that the altercation between Draymond Green and Jordan Poole stemmed from Poole's apparent cocky behavior since training camp began. Poole, coming off a breakout year which culminated in an NBA title is due to receive a massive extension and is allegedly increasingly becoming a diva.
This set off Draymond who confronted him and allegedly called him a "b****" several times throughout the course of practice before hauling off and punching him in the face when Poole finally shot back.
Per TMZ: "Things escalated when Poole allegedly said, "You know what it is, Draymond." -- seemingly bragging over the contract situation -- and Draymond got in Poole's face, allegedly saying, "No I don't know, what is it?""
Source: Tmz.com