Manchester United have had a lot of trouble at left-back this past season and are expected to be in the market for another this summer. Tyrell Malacia was supposed to be Manchester United’s fix for Luke Shaw’s ongoing injury troubles. This past season, Malacia endured his own injury nightmare, failing to make a single matchday squad. All this did was shine a closer spotlight on Shaw, who suffered four separate injuries and did not play a single game after mid-February. Next season, United will feel like they can’t rely on either. Additional cover is required, and one promising name is already …