Manchester United reportedly have Marc Cucurella, Marcos Alonso, and Sergio Reguilon on their list as they hunt for a new left-back before Friday's deadline.
Luke Shaw's muscle injury could keep him out until November and it has left United desperately under-staffed at left-back, what with Tyrell Malacia also on the sidelines and Brandon Williams on loan at Ipswich.
Diogo Dalot struggled to fill in as a makeshift replacement in their 3-2 win over Nottingham Forest on Saturday and Erik ten Hag would not want the club's ambitions dented by a lack of cover.