Barcelona captain Leo Messi refused to shake the hand of ref Jesus Gil Manzano at the end of their draw with Girona.
Barca were angry after the first-half dismissal of Clement Lenglet.
Marca says Gerard Pique had already expressed his dismay with the match official in the tunnel at half time and he wasn't alone.
After the game, which saw Barcelona drop two points at the Camp Nou, Messi approached the referee and despite Gil Manzano offering his hand, the Argentine refused and headed back to the dressing room.
The result ended 2-2, with Pique grabbing a valuable equaliser.