Real Madrid coach Jose Mourinho has refused to divulge whether he will recall goalkeeper Iker Casillas against Real Sociedad on Sunday.
The Portuguese left out of the Spain international from his starting lineup against Malaga before the winter break in a game that the defending Spanish champions lost 3-2.
"To be permanently in the comfort zone isn't good for players," Mourinho told reporters. "All positions on the pitch are about confidence, it is fundamental for all the players, not only for the keepers.
"This translates into performance, but just as confidence is important so is competition, and we will try and strike that balance.
"[Casillas and Antonio Adan] don't even know who is going to play in goal yet. All I can say is, whoever plays against Real Sociedad will not play on Wednesday [in the Copa del Rey]."
Madrid are currently 16 points behind leaders Barcelona in third place.