a one-piece molded protective shell having sidewalls covering substantial portions of the ankles and sides of the boot, the sidewalls connected by an instep-covering top portion and spaced by an open bottom and contiguous split rear, the shell comprising heel-cupping sidewall portions adapted to partially wrap around opposite sides of a rounded heel portion of a hockey skate boot, the heel-cupping sidewall portions capable of being flexed apart by hand to fit the cover diagonally over a top instep portion of a boot, the shell having a molded-in flex bias along a diagonal line from the heel-cupping portions toward the instep-covering top portion tending to draw the heel-cupping sidewall portions together to grip a rounded heel portion of a boot when the heel-cupping sidewall portions are released; and,

spaced pads on an underside of the shell, the spaced pads spacing the shell from the boot.