An article of footwear comprising: a sole structure; and an upper that includes an expandable warp knit element, the warp knit element formed of unitary knit construction, the warp knit element defining a warp direction and a weft direction, the warp knit element expanded to an expanded position from a contracted position to at least partially define the upper, the warp knit element including a plurality of strap members that are configured to be substantially non-extensible along the warp direction for providing support to the article of footwear; the plurality of strap members including a first strap member and a second strap member, each of the first strap member and the second strap member including a leading edge (51, 55) and an opposite trailing edge (53, 57); the first strap member and the second strap member being: (i) separated along a portion of a length of the first and second strap members (28, 30) by an opening; and (ii) at least partially joined at a junction (32, 34); the junction (32, 34) being formed of unitary knit construction with the first strap member and the second strap member; the first strap member including a first leading edge and a first trailing edge, the first trailing edge extending from the junction generally in the warp direction; the second strap member including a second leading edge and a second trailing edge, the second leading edge extending from the junction (32, 34) generally in the warp direction; the second leading edge and the first trailing edge cooperating to define the opening that separates the first strap member and the second strap member; the opening being a slit when the knit element is in the contracted position; the opening having a larger area than the slit when the knit element is in the expanded position. a sole structure; and an upper that includes an expandable warp knit element, the warp knit element formed of unitary knit construction, the warp knit element defining a warp direction and a weft direction, the warp knit element expanded to an expanded position from a contracted position to at least partially define the upper, the warp knit element including a plurality of strap members that are configured to be substantially non-extensible along the warp direction for providing support to the article of footwear; the plurality of strap members including a first strap member and a second strap member, each of the first strap member and the second strap member including a leading edge (51, 55) and an opposite trailing edge (53, 57); the first strap member and the second strap member being: (i) separated along a portion of a length of the first and second strap members (28, 30) by an opening; and (ii) at least partially joined at a junction (32, 34); the junction (32, 34) being formed of unitary knit construction with the first strap member and the second strap member; the first strap member including a first leading edge and a first trailing edge, the first trailing edge extending from the junction generally in the warp direction; the second strap member including a second leading edge and a second trailing edge, the second leading edge extending from the junction (32, 34) generally in the warp direction; the second leading edge and the first trailing edge cooperating to define the opening that separates the first strap member and the second strap member; the opening being a slit when the knit element is in the contracted position; the opening having a larger area than the slit when the knit element is in the expanded position.