The ornamental design for footwear sole portion, as shown and described.
FIG. 1 is a perspective view of the footwear sole portion embodying the new design;
FIG. 2 is a front view thereof;
FIG. 3 is a right side view thereof; and,
FIG. 4 is a left side view thereof.
FIGS. 1–4 show features of an article of footwear in phantom lines. These features are shown for environmental purposes and do not form any part of the claimed design. Further, the phantom lines immediately adjacent the solid-line portions of the design form the boundary of the design, with the phantom lines forming no part of the claimed design.