As Mugen flew off, it left Josh with a sense of disappointment, he'd have to find a way to get close enough to Raditz himself. The opportunity had presented himself when a human and Mugen both started trying to draw the sayians attention. 
He charged the sayian using his hidden ki to avoid detection and made an attempt to latch onto him if he missed he could launch an Android kick and stun the sayian giving others a split second to attack.