FIG. 1 is a bottom perspective view of a portion of an article of footwear showing my new design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a front elevational view thereof; and,

FIG. 6 is a rear elevational view thereof.

The broken-line showing of FIGS. 1-6 is for illustrative purposes only and forms no part of the claimed design.