A rotary cutterbar assembly (200) and a disc guard (224) for coupling to a housing of the cutterbar assembly (200) is disclosed. The cutterbar assembly (200), comprising: a housing (202) including a front edge (206), a first and second tab (302, 304), and a first stop (404), where the first and second tab (302, 304) is defined along a plane (208) at the front edge (206) and the first stop (404) is disposed offset from the plane (208)； at least one disk (214) rotatably coupled to the housing (202), the at least one disk (214) including at least one knife (216) rotatably coupled thereto； and a disk guard (224) coupled to the housing (202) at the first and second tabs (302, 304), the disk guard (224) extending in a direction of travel beyond the front end (206) of the housing (202)； wherein, when the disk guard (224) contacts an underlying object and is forced toward the housing (202), a first receiver (802) of the disk guard (224) contacts the first stop (404) to restrict deflection of the disk guard (224) relative to the housing (202). A disk guard (224) for coupling to a housing (202) of a cutterbar assembly (200), comprising: a body (800) defining a front edge (810), the front edge (810) disposed in a first direction to form a nose portion (312)； a first end of the body (800) defining a first receiver surface (802) adapted to contact a first surface of a housing (202)； a second end of the body (800) defining a second receiver surface (804) adapted to contact a second surface of the housing (202), the first end and second end being spaced from one another； a planar surface (814) of the body (800) disposed rearward of the front edge (810)； a first offset surface (818) disposed rearward of the front edge(810) and integrally coupled with the first receiver surface (802)； and a second offset surface (820) disposed rearward of the front edge and integrally coupled with the second receiver surface (804)； wherein, the first and second offset surfaces (818, 820) are configu
