Madrid: Barcelona start the year a point adrift of Real at the top, but having played a game more.
The Catalans also face a potentially tricky trip away to David Moyes' Real Sociedad on Sunday and have had little time to prepare for the game as a group following the Christmas break.
Lionel Messi, Neymar and Dani Alves only returned to training on Friday. Moyes has urged his players to summon the spirit that saw them defeat Real and Atletico at home.
"We respect Barcelona, they are a good team, but they are coming to San Sebastian and we have to show them this is not an easy place to come and win," he said.