A vehicle rocker assembly is provided. The vehicle rocker assembly may include an outer panel, a side sill, and an insert. The side sill may define at least two cavities with the outer panel. The insert may be disposed in the cavities. The insert may include a longitudinally extending U-shaped carrier and a plurality of reinforcement members attached to the U-shape carrier. The plurality of reinforcement members may be spaced apart from a bottom of the U-shaped carrier by a predetermined distance.