An apparatus for successively releasing balls into a wellbore during wellbore operations is disclosed. The apparatus has a radial housing having at least one radial ball array having two or more radial bores. Each radial bore houses a ball cartridge adapted to receive and release balls and an actuator for operably aligning or misaligning the ball cartridge with an axial bore in fluid communication with the wellbore. The ball cartridge is moveable along the radial bore and is operable between an aligned position, for releasing a ball and a misaligned position for storing the ball.