A footwear article with one or more polymer reinforcing elements comprising: a seamless upper comprised of a plurality of materials that includes a polymer-reinforcing fiber (31, 34), the seamless upper formed in a unitary knit construction (33, 55, 59) through a knitting process performed by a knitting machine, wherein the unitary knit construction comprises an upper main body comprising a plurality of portions, at least one portion of the plurality of portions in the unitary knit construction comprises the polymer-reinforcing fiber that is formed by knitting one or more reinforcement knitting yarns during the knitting process; wherein each of the plurality of portions is knitted into shape through the knitting process and is connected to another portion of the unitary knit construction seamlessly by knitting stitches that are generated in the knitting process; wherein the plurality of portions of the unitary knit construction comprise: a lateral side portion; a toe portion; a medial side portion; an ankle portion; an instep portion; and a heel portion, wherein further an angle between the heel portion and the instep portion is formed through the knitting process, wherein: the heel portion is formed by an insert generated in the knitting process; the insert being manipulated in the knitting process; and the insert having loops, wherein the insert has been produced by the knitting machine moving stitches for the heel portion to an alternative needle bed and subsequently attaching the loops of the insert to the medial side portion and the lateral side portion to attach the insert to the medial side portion and the lateral side portion. a seamless upper comprised of a plurality of materials that includes a polymer-reinforcing fiber (31, 34), the seamless upper formed in a unitary knit construction (33, 55, 59) through a knitting process performed by a knitting machine, wherein the unitary knit construction comprises an upper main body comprising a plurality of portions, at least one portion of the plurality of portions in the unitary knit construction comprises the polymer-reinforcing fiber that is formed by knitting one or more reinforcement knitting yarns during the knitting process; wherein each of the plurality of portions is knitted into shape through the knitting process and is connected to another portion of the unitary knit construction seamlessly by knitting stitches that are generated in the knitting process; wherein the plurality of portions of the unitary knit construction comprise: a lateral side portion; a toe portion; a medial side portion; an ankle portion; an instep portion; and a heel portion, wherein further an angle between the heel portion and the instep portion is formed through the knitting process, wherein: the heel portion is formed by an insert generated in the knitting process; the insert being manipulated in the knitting process; and the insert having loops, wherein the insert has been produced by the knitting machine moving stitches for the heel portion to an alternative needle bed and subsequently attaching the loops of the insert to the medial side portion and the lateral side portion to attach the insert to the medial side portion and the lateral side portion. the heel portion is formed by an insert generated in the knitting process; the insert being manipulated in the knitting process; and the insert having loops, wherein the insert has been produced by the knitting machine moving stitches for the heel portion to an alternative needle bed and subsequently attaching the loops of the insert to the medial side portion and the lateral side portion to attach the insert to the medial side portion and the lateral side portion.