A knotless bone anchor and method for securing soft tissue, such as tendons, to bone, includes a plurality of discrete components. In one variation of the invention, the bone anchor includes a proximal toggle component, an intermediate plug component, and a distal sleeve component. Suture is looped around the plug component and once the anchor is actuated, the suture is compressed between the plug and the sleeve components. Advantageously, one or more of the components may be made of a biocompatible polymer. The polymeric components may be detachably joined to a drive shaft using a plurality of sacrificial fills. The sacrificial fills are broken or severed during deployment of the anchor. Related instruments and methods are also described.