12:05 PM PT -- 5/5 -- Green now knows what his gesture will cost him ... the NBA announced Thursday it's officially fined the Dubs star $25,000.
Draymond Green unloaded a double-barrel, middle-finger salute on some heckling Grizzlies fans during a playoff game Tuesday night ... and he refused to apologize for it afterward, admitting the gesture "felt really good."
The Warriors star flipped the birds just minutes into the Dubs' playoff game against Memphis in Nashville ... shortly after he had been inadvertently elbowed in the face.
Following the game, Green said he didn't regret his actions one bit ... explaining he'll happily pay the fine that NBA officials will inevitably hand his way over it all.
"If you're going to boo somebody who got elbowed in the eye and had blood running down their face, you should get flipped off," Green said. "So, I'll take the fine. I'll go do an appearance and make up the money."
Courtesy of NBA
"But," he added, "it felt really good to flip them off."
No word on what it'll cost Green (Kyrie Irving was fined $50,000 for a similar gesture last month) ... but he told media members the price tag truly won't matter.
"I make $25 million a year," he said. "I should be just fine."
As for the action on the court, Green's Warriors ended up taking the L -- falling to Ja Morant and the Grizzlies, 106-101 ... much to Grizzlies fans' delight.