An article of footwear comprising: a sole structure; and an upper having a longitudinal axis X, wherein the upper is coupled to the sole structure, the upper including a lower edge that is disposed adjacent to the sole structure, the upper further including a collar defining an opening to a void within the upper, the collar defining an upper edge of the upper that is spaced away from the lower edge, wherein the upper comprises: a forward portion and a heel portion; wherein the heel portion is separate from the forward portion, the heel portion comprising a knitted component of unitary knit construction, the knitted component at least partially defining the upper edge and the lower edge of the upper, the knitted component of the heel portion having a first zone, a second zone, and a third zone, wherein the first zone has a first amount of stretch resistance, the second zone has a second amount of stretch resistance, and the third zone has a third amount of stretch resistance, and wherein the first amount of stretch resistance of the first zone is larger than the second amount of stretch resistance of the second zone, wherein the second zone is substantially centered on the longitudinal axis X and substantially centered within the first zone; and wherein the knitted component includes a first side edge that is attached to the forward portion along a first side and a second side edge that is attached to the forward portion along a second side, and wherein the article of footwear is characterized in that the second amount of stretch resistance of the second zone is larger than the third amount of stretch resistance of the third zone. a sole structure; and an upper having a longitudinal axis X, wherein the upper is coupled to the sole structure, the upper including a lower edge that is disposed adjacent to the sole structure, the upper further including a collar defining an opening to a void within the upper, the collar defining an upper edge of the upper that is spaced away from the lower edge, wherein the upper comprises: a forward portion and a heel portion; wherein the heel portion is separate from the forward portion, the heel portion comprising a knitted component of unitary knit construction, the knitted component at least partially defining the upper edge and the lower edge of the upper, the knitted component of the heel portion having a first zone, a second zone, and a third zone, wherein the first zone has a first amount of stretch resistance, the second zone has a second amount of stretch resistance, and the third zone has a third amount of stretch resistance, and wherein the first amount of stretch resistance of the first zone is larger than the second amount of stretch resistance of the second zone, wherein the second zone is substantially centered on the longitudinal axis X and substantially centered within the first zone; and wherein the knitted component includes a first side edge that is attached to the forward portion along a first side and a second side edge that is attached to the forward portion along a second side, and wherein the article of footwear is characterized in that the second amount of stretch resistance of the second zone is larger than the third amount of stretch resistance of the third zone. a forward portion and a heel portion; wherein the heel portion is separate from the forward portion, the heel portion comprising a knitted component of unitary knit construction, the knitted component at least partially defining the upper edge and the lower edge of the upper, the knitted component of the heel portion having a first zone, a second zone, and a third zone, wherein the first zone has a first amount of stretch resistance, the second zone has a second amount of stretch resistance, and the third zone has a third amount of stretch resistance, and wherein the first amount of stretch resistance of the first zone is larger than the second amount of stretch resistance of the second zone, wherein the second zone is substantially centered on the longitudinal axis X and substantially centered within the first zone; and wherein the knitted component includes a first side edge that is attached to the forward portion along a first side and a second side edge that is attached to the forward portion along a second side, and wherein the article of footwear is characterized in that the second amount of stretch resistance of the second zone is larger than the third amount of stretch resistance of the third zone.