Floyd Mayweather is spitting more venom at Dana White -- calling him a "small boss" who used to carry his bags back in the day.
Mayweather went off on the UFC honcho at the Barclays Center this weekend -- once again trashing Dana's $25 MILLION offer to fight Conor McGregor ... this time, he took a stroll down memory lane.
"Dana White ... he was a player. He was a boss ... but he was a small boss."
"I can remember Dana White used to hang around me and Jeff Mayweather and carry my bags."
Mayweather says he used to be cool with White until ... "all the sudden he cut his head bald and he's such a tough guy. He's such a tough guy."
Just a few days ago, Dana told TMZ Sports why Floyd would be a fool to shoot down the offer.