Juan Mata and Ander Herrera may consider their futures at Old Trafford if Louis van Gaal wins an increasingly desperate struggle to save his job.

The Dutchman faces a potentially defining run of games over the Christmas period when he must also try to win back a dressing room that harbours widespread doubts about his methods.

Wayne Rooney and Michael Carrick confronted Van Gaal early in the season to register complaints on behalf of the squad about his regimented tactics and suffocating style of play, and the concerns of players have mushroomed in recent months.

United have won just three of their past 13 matches, during which time they were eliminated from the Champions League and Capital One Cup and dropped out of the Barclays