The La Liga leaders had hoped to postpone the match due to acts of violence within the Catalonia region, which left more than 750 injured in clashes between the public and police after a controversial referendum for independence was declared illegal by the national government.
After being threatened with a six-point deduction, though, Barca chiefs felt that it would be best to play the game in front of an empty Camp Nou.
Bartomeu insists that safety was never an issue, but the decision was taken to play in front of the deserted stands to show a united front with voters in Catalonia.
"[Playing without fans] was a measure to show our rejection of what took place today," he told beIN Sports. "This is not a security issue, the police gave us permission to play, but we wanted to show that this game was different because of everything that is happening in Catalonia and the lack of liberty we have been suffering from.
"We are worried and very sorry. We decided that instead of postponing the game, which is what we wanted, we'd play behind closed doors. That way we show our concern for the situation and send our support to those who have been unable to exercise the right to freedom of expression."