Kevin Hart -- Sorry Adidas ... James Harden Will Return to Nike

James Harden shouldn't trash his old Nikes just yet ... 'cause Kevin Hart predicts the NBA star will eventually COME BACK to the Swoosh ... despite his $200 million deal with Adidas.

Hart was at the Venice Beach Recreation Center for a Nike+ Run Club event -- when he pledged his allegiance to the shoe brand and predicted it's just a matter of time before Harden returns to the Nike fam.

It's not the craziest theory ... considering Harden refused to junk his Nikes after he signed his contract with Adidas ... even after the people at Adidas let him know it was pissing them off.