Gareth Bale fouled Rafinha Alcantara in the 72nd minute of Real Madrid's match at home to Celta Vigo on Sunday night, yet referee Javier Alberola Rojas deemed it only worthy of a yellow card.
The Welshman went in aggressively and could have done damage to Rafinha, but fortunately the Celta midfielder was able to continue afterwards.
"Alberola Rojas was wrong to only show a yellow to the Welsh player," Juan Andujar Oliver, MARCA's resident referee expert, told Radio MARCA.
"It's a very hard tackle that deserves a red card.
"It ends a promising Celta move with an excessively aggressive tackle."