An off-center impact structure (a frame protrusion rupture mitigating structure) has a first end section, a mid-section and a second end section. The first end section is fixedly attached to an attachment section of a vehicle front side member. The mid-section extends laterally outward and defines an arcuate shape curving forward from the first end section and laterally outboard. The second end section of the off-center impact structure is located forward of the attachment section. The mid-section has a forward-facing surface formed with a plurality of vertically oriented recesses. In response to an off-center impact event where impacting force is applied to a distal end of the second end section, the off-center impact structure deforms bending along the mid-section with at least a portion of the vertically oriented recesses expanding in a bellows-like manner absorbing impact energy such that the second end section is moved rearward.