Real Madrid are believed to be keeping tabs on Villarreal defender Alfonso Pedraza as they consider making improvements at left back.
Marcelo has been one of the world's best left backs throughout Madrid's Champions League dominance of recent seasons, but he is now 30 years old and has been hampered by a number of injury concerns in the early part of this campaign.
21-year-old Sergio Reguilon deputised for the Brazilian in Saturday's win over Real Valladolid. Another available option is Theo Hernandez, although he is currently out on loan at Real Sociedad.
The 22-year-old impressed while on loan at Alaves last season and he has featured in all but one of Villarreal's matches in La Liga this season.
He carries an attacking threat and is also capable of playing on the left wing. In his last three matches, he has provided two assists before scoring his first goal of the season against Levante at the weekend.
Pedraza also spent time on loan at Leeds United in 2017, scoring once in 14 league appearances for the Championship side.
Whether or not Real decide to pursue a move for Pedraza may depend on who is appointed as their permanent manager following the sacking of Julen Lopetegui.
Caretaker boss Santiago Solari is the current favourite, but Roberto Martinez and Mauricio Pochettino also under consideration.