Kendrick Perkins says James Harden was too busy strip club hoppin' to care about the 2012 NBA Finals ... admitting, "We couldn't get that motherf***er to buy a bucket in that motherf***er."
The ex-NBA big man went IN on his former OKC Thunder teammate on Matt Barnes and Stephen Jackson's "All The Smoke" podcast recently ... saying everyone brought their "A" game against LeBron James and the Miami Heat Big 3.
... except Harden.
"Man, James ain't give a s*** and you know why," Perk said ... "Motherf***ing King of Diamonds and everything cut a hole in his hands."
Perk points out Harden had no issues during the Western Conference Finals against the Spurs that same year ... 'cause there weren't any outside distractions.
"In San Antonio, you didn't have a damn thing to do," Perkins added. "S***, we got to motherf***ing Miami, it was every-motherf***ing-thing to do. We couldn't get that motherf***ker to buy a bucket in that motherf***er."
The numbers don't lie -- Harden averaged 12.4 points in the 5-game series, after averaging 18.5 per game in the previous round against the Spurs.
Of course, the Heat went on to win it all in Game 5 -- securing LeBron's first championship ... and Harden was later traded to Houston, where he became a strip club legend.
Now, Harden's Big 3 in Brooklyn is hoping to make their own Finals run ... and we're assuming Kevin Durant and Kyrie Irving will try like hell to keep him out of the booty clubs.