An insert for an impingement plate and an impingement plate including the insert are disclosed. The impingement plate includes a plurality of cooling holes therein. The insert includes a body including an opening extending longitudinally therethrough. The body also includes a discharge end configured for positioning in an impingement air plenum between the impingement plate and an upstream surface of a combustor cap plate; a flexible insertion end configured for insertion into a respective cooling hole of the plurality of cooling holes; and a fixation element between the discharge end and the flexible insertion end. The fixation element has an outer dimension configured to fixedly couple the body in the respective cooling hole.