Memphis Grizzlies -- Honoring B.B. King ... Before HUGE Playoff Game

B.B. King might be gone, but the Memphis Grizzlies are making sure he's not forgotten ... taking time out to remember the music titan before tonight's HUGE playoff game ... TMZ Sports has learned.

We spoke to the Grizzlies reps who tell us ... before the team takes on Golden State in Game 6 of the Western Conference semifinals tonight ... they'll honor the hometown hero who passed Thursday at age 89.

The team didn't wanna give away too many specifics about how they're planning to honor King -- but are hoping fans of both basketball and music enjoy the huge surprise they have in store.

R.I.P. B.B.