Doug

Rocky Rivers, also known as Doug, is the star baseball player of the Rockets. Rocky wears a Baseball Uniform with the number 00 on the back and a baseball cap with the letter "R" on the front of it. Rocky Rivers struck out Murdock and Pepper Johnson by hitting them with the ball. Johnson got angry about it, so a fight broke out, but Yamcha beat everyone up, including Rocky Rivers. (Source: Dragon Ball Wiki)