The Reds begin our Group E schedule with a home game against the San Sebastian side, looking to make a positive start in the competition and build on a four-game winning run in the Premier League.
There is the prospect that Ten Hag will rotate his squad, with so many players keen for an opportunity to impress, but La Real, who drew with Atletico Madrid at the weekend in La Liga, are likely to provide a stiff test.
When asked about the latest on Anthony Martial at his press conference, the boss told reporters: "Yes, he is still out.