Sunderland are thought to be closing in on their third signing of the summer transfer window. So far this summer, Sunderland have two new signings through the door, with both being fee agents. Goalkeeper Simon Moore joined earlier on before Alan Browne signed on, bringing with him a wealth of Championship experience. Sporting director Kristjaan Speakman may have his work cut out for him this summer following what was a prolonged and arduous four-month search for a new head coach, which ended with the appointment of Regis Le Bris. Since, Sunderland have been knocked back in their efforts to sig…