A vertebral disc prosthesis, a method of implanting a prosthesis and a deployment device is provided. The prosthesis may be implanted into the interior region of the vertebral disc so as to displace existing vertebral tissue, such as NP. The size or amount of the prosthesis inserted into the interior region of the vertebral disc may be a characteristic of the disc or the prosthesis. For example, the amount or size of prosthesis inserted into the disc may be dependent upon restoring the functionality of the disc (e.g., the ability of the disc to transfer nutrients or otherwise survive, the ability of the disc to carry the required loads and absorb stress or the reduction of pain). Restoring disc function may be determined by the resulting disc height desired, the resulting disc pressure desired or the resulting disc volume desired. The prosthesis may be sized or positioned within the interior of the vertebral disc such that it is spaced from at least one of the end plates of the vertebral disc. The prosthesis may be formed of a material having a compression strength that is less than 4 mn/m.sup.2. A deployment device may be used to facilitate placement of the prosthesis within the vertebral disc. The prosthesis may include a grouping of multiple components that can be deployed as group.