Atletico Madrid's Fernando Torres (R) kisses the pitch as he celebrates a goal with his teammate Raul Garcia during their Spanish King's Cup soccer match against Barcelona at Vicente Calderon stadium in Madrid January 28, 2015. [Photo/Agencies]

The Atletico players were angry with the performance of the referee but Busquets felt that neither side benefited from his decisions.

"I've also been told that the penalty conceded by Mascherano shouldn't have been given. There were mistakes made against both teams," he told reporters.

"There was little control in the game in the first half. It was a good half for the fans and we took advantage of the openings that we had."

Despite the fact they were chasing the game, Atletico coach Diego Simeone said he asked his players to show more restraint at half time.

"I told them not to take risks and concentrate on not conceding goals," he told a news conference.

"I thought it was the best decision for the team and the club after the way the first half went."

Barca will face the winners of Getafe and Villarreal who play on Thursday with the latter leading 1-0 from the first leg.

Athletic Bilbao are at home to Malaga having drawn 0-0 in the first leg and Espanyol travel to Sevilla leading 3-1.