Izzet was stretchered off the St Andrews pitch against Graeme Souness' side with a bad knee injury whilst his replacement Clemence finished the game with a calf strain.
With the midfield pair struggling for fitness that could open the door for a first league start for Darren Anderton. The former England international has made only one first team appearance since his move to St Andrews in August. Anderton put in a man-of-the-match performance against Lincoln in the Carling Cup tie at St Andrew's last month.
Meanwhile, Stan Lazaridis has now been out of action for almost seven weeks with a thigh strain and it remains to be seen whether manager Steve Bruce is prepared to throw the Aussie winger back into the fold against United. Next weekends game at Southampton maybe a more realistic date for the Socceroo to make his comeback.