Valencia have called on Spain's footballing authorities to do more to tackle racism following the alleged abuse of their player Mouctar Diakhaby on Sunday.
The Valencia team walked off the field during their 2-1 La Liga defeat at Cadiz after defender Diakhaby claimed to have been racially abused by the home side's Juan Cala.
They later returned to complete the game but without Diakhaby, who was substituted. The club said they did not ask the players to play on and they only did so after being informed by the referee of potential sanctions.
Valencia president Anil Murthy said in a strong statement on the club's website: "In our game against Cadiz, we witnessed a flagrant incident of racism. There is no other way to describe it.
"This type of behaviour should not be tolerated in football and in society in general, and we at Valencia CF condemn racism in any form. We fully support our player.
"We spoke with LaLiga to encourage them to also see their investigation through to the end. This incident cannot be left behind, and cannot be repeated with any other player for any other team.
"We are saddened that, following the incident, there was no reaction to stop the game and that it was our players who were the ones to leave the field of play.
"We are proud of the reaction from our team and we still do not understand why Diakhaby, the recipient of this racial insult, received a yellow card.
"We also do not understand why the players had to return to the pitch due to the regulations not protecting the victims and the team in such cases.
"This must change. Changes have been made in other leagues and now the same must be done in Spain. We cannot turn a blind eye to something as serious as racism.
"It is time for a change and Valencia CF will go all the way in support of our player and the fight against racism. A step back in the fight against racism was taken yesterday."
The incident occurred in the first half of the match at the Estadio Ramon de Carranza.
Play was halted after Diakhaby reacted furiously following a clash with Cala and remonstrated with the referee.
Valencia issued a photograph on Monday of their squad standing behind Diakhaby in a show of solidarity.
Cala is reportedly set to give his version of events at a press conference on Tuesday.