Sunderland have a number of players in demand right now. But ahead of January, it seems like one name is doing the rounds more than most. During the summer, Sunderland sold Jack Clarke for a reported fee of up to £20million, potentially marking the start of regular, big money player sales at the Stadium of Light. Sunderland under Kristjaan Speakman are making a very nice habit of buying young players for very little and turning them into valuable assets. Right now, there’s a handful of players in the Sunderland first-team squad who were signed for very little, or have come through the academy,…