Master P is already predicting his hoops star son, Mercy Miller, is gonna be a baller at the University of Houston -- telling TMZ Sports, he could be just as great as Hakeem Olajuwon!
And, he's only 15 years old ... playing guard at Minnehaha Academy in Minneapolis but made an early commitment to play college ball for the Houston Cougars.
"His favorite teams was University of Houston and Duke," P tell us, "That was his final choices and to be able to do that as a young kid right now .