NBA's Joel Embiid to Rihanna ... 'I Love You ... Hit Me Up' (VIDEO)

Joel Embiid is taking ANOTHER shot at his celebrity crush -- this time, professing his love in a video message to Rihanna ... "I love you."

Embiid's been after Rihanna for a while ... ever since she allegedly shot him down in 2014 and told him to come back when he's an All-Star.

Well, he killed it this season and could win Rookie Of the Year ... and clearly, he's got the confidence to double down on his efforts to court the pop star.

Still, Embiid's staying humble ... and told our photog, it's his 76ers teammate, Dario Saric, who should get R.O.Y.