Caron Butler says there's a diamond in the rough in the NBA playoffs ... a guy he says is "so special" the Trail Blazers better not sleep on him -- and that dude is Nikola Jokic.
The 7-footer from Serbia has emerged a force to be reckoned with this season -- and Butler says it's no fluke.
"He's so special," Butler tells TMZ Sports ... "I spent some time with the Denver Nuggets and his versatility is just amazing because he's able to shoot the basketball, ultimately facilitate and he has a high basketball IQ. He's just tough to stop."
24-year-old Jokic put his talents on display during Game 1 of his series with Portland -- pounding the Blazers for 37 points, 6 assists and 9 rebounds.
Game 2 is set for Wednesday night -- and Caron expects more of the same ... Jokic domination.
He even dished out a mini-pump up speech for the guy ... not that he needs it!