Youngsters McAllister and Spence are both products of the Phoenix Ulster Rugby Academy.
Prop Paddy McAllister ,who was awarded a development contract ahead of the start of the current season, made his Ulster debut coming on as a replacement against the Ospreys in September. The Ballynahinch player, who has has represented Ireland at Schools, U19 and U20 level has featured regularly in the Ulster match day squad this season.
Centre Nevin Spence also joined the Ulster Squad on a development contract this summer after featuring for Ireland U20s in the Junior World Championship in Argentina. The former U16 Northern Ireland football international got his first Ulster start against Glasgow last April and has started six matches for Ulster so far this season, scoring a memorable try in Ulster's defeat of Bath at The Rec last month as well as one last Friday night against Treviso.