Portion of a golf club head

FIG. 1 is an elevational view of a portion of a golf club head showing our new design;

FIG. 2 is a heel end perspective view thereof;

FIG. 3 is a toe end perspective view thereof;

FIG. 4 is a toe end view thereof; and,

FIG. 5 is a bottom view thereof.

The broken line representation of various features and the remainder of the golf club head forms no part of the claimed design.