Ronald Koeman fumed about the standard of refereeing in Spain after he was sent off as Barcelona drew 0-0 with Cadiz on Thursday.
Koeman claimed he was sent off for pointing out to the fourth official that there was a second ball on the pitch late on.
"It's better not to speak about that because if everyone sees a second ball on the pitch except (the ref), it speaks for itself," he told Movistar.
Later, in his press conference, he added: "In this country, they send you off for nothing.
"Everyone saw the two balls on the pitch except him. I told the fourth official there were two balls... but here they send you off for nothing, nada."
Despite not winning in Cadiz, a result that further increased the pressure on Koeman, the coach was happy with his players.
"I think in general the team was good," he added. "We had the ball but struggled to create chances, although we did have the best chances. We were there until the last minute.
"I can't complain about the attitude, I'm very happy with the team's attitude. We were superior until the Frenkie de Jong red; then we had more problems with 10 men, but we still had the best chances. We lacked the efficiency to take them. If you don't score, you don't win."