Barca lost 2-1 at Athletic Bilbao in a King's Cup last-16 first-leg game on Thursday. Pique and Neymar had penalty appeals turned down while Athletic forward Aritz Aduriz, who scored the first and made the second goal, escaped a red card for striking Barca defender Samuel Umtiti.
Athletic ended the game with nine men as Raul Garcia and Ander Iturraspe both earned second yellow cards, but Pique still criticised the performance of referee David Fernandez Borbalan.
The Spain international, who has a reputation for stoking the long rivalry between Barca and Real, also complained that Zinedine Zidane's side had a soft penalty awarded in their 3-0 win over Sevilla on Wednesday.
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"We want to play football and not roulette, which is what this type of refereeing provokes. The penalty claims by Neymar and me are clear but we already know how this works," Pique told reporters.
"We all saw what happened in Madrid's game with Sevilla, I hope referees improve their standards."
Barca have been the scourge of Athletic in the last two King's Cups, beating the Basques in the 2015 final and knocking them out at the quarter-final stage last season but they face elimination unless they can turn the tie around next Wednesday.
"The tie is wide open and we hope we can go through at the Nou Camp," Pique said.
"We need to have one of our great nights there and for the fans to help us turn it around because once again our aim this season is to win everything."
(Reporting by Richard Martin, editing by Ed Osmond)
