A golf ball component, such as a golf ball cover layer, formed from a high or increased melt index thermoplastic polyurethane, polyurea or polyurethane/polyurea is disclosed. The cover layer may be relatively thin (i.e., 0.075 or less, preferably 0.050 inches or less, more preferably less than 0.040 inches, even more preferably less than 0.030 inches). In addition, an operation in which the outer cover is exposed to an isocyanate solution is described to improve certain physical properties of the resulting golf ball.