The two players had been verbally sparring prior to some pushing, which escalated when Green took a swing and made contact with Poole, sources said. Team officials are reviewing the episode.
Poole wasn't hurt by the punch and completed his workout before leaving the practice floor on Wednesday, sources said.
Green has a history of challenging teammates, past and present, in practice and game settings. It is possible there could be some punishment meted out to Green for escalating the practice encounter Wednesday.
The Athletic was first to report the incident.