Real Madrid coach Santiago Solari admitted his team must do more to restore the faith of the fans after 30,000 empty seats at the Bernabeu for Sunday's loss to Real Sociedad.
A season-low crowd of 53,412 watched the 2-0 defeat, considerably short of the stadium's capacity of 81,044.
It left Real sitting fifth in the La Liga table, some 10 points adrift of rivals and leaders Barcelona, as well as Atletico Madrid, Sevilla and Alaves.
"We must try to ensure they return to the stadium in future games," Solari said.
"We know that our situation in this moment is not what we want it to be, we have dropped too many points and are not in a position where we are capable of reaching."
Real were whistled off by those supporters who did attend after Sociedad claimed their first victory at the Bernabeu since 2004.
They fell behind early on when Willian Jose converted a penalty after Casemiro ran into Mikel Merino inside the area.
Lucas Vazquez was dismissed for a second yellow card following a foul on Merino before Real were denied a penalty when Vinicius went down in the box after dribbling around goalkeeper Geronomi Rulli.
Sociedad then secured their victory when substitute Ruben Pardo scored a late second.
Solari added: "Our objective is to win every game and we thought we could win this too, even when we were reduced to 10 men, but unfortunately we could not score from a number of good opportunities."
"We played well in the first-half but could not maintain this level and things just did not go right for us, including the officiating decisions."
"It seemed like a clear penalty for the challenge on Vinicius, who coincidentally enjoyed a really strong game for us, he was the one positive from our point of view."
"We do not want to talk about referees but we are confused as to why VAR was not used for an incident like that."
Real return to action against Leganes in the last-16 of the Copa del Rey on Wednesday evening before a visit to Real Betis in the league next Sunday.