By Jamie Spencer Manchester United are keen to strengthen their depth at full-back in upcoming transfer windows, having initially made a point of prioritising attacking players during the summer transfer window. United brought in four attacking players this summer – Lucia Garcia, Adriana Leon, Rachel Williams and Nikita Parris – as well as midfielder Grace Clinton. The arrivals of Aissatou Tounkara and Maya Le Tissier have also strengthened the centre of defence. Le Tissier had been excelling at right-back for former club Brighton but has quickly made the seamless transition to centre-back, wh…