Bruce Maxwell -- the only MLB player to kneel during the national anthem -- went off on cops during his Oct. 2017 arrest ... telling police he took a knee to protest "y'all motherf*ckers."
As we previously reported, Maxwell was arrested for aggravated assault at his AZ home after allegedly pulling a gun on a Postmates driver.
When cops arrived, Maxwell -- not wearing a shirt -- began berating the police officers.
"Think I'm intimidated? Cool. Cool. I hope so. I’m not afraid of f*cking none of y’all n*ggas. I don’t give a f*ck.