Valencia walked off the pitch during Sunday’s 2-1 La Liga defeat at Cadiz after an alleged racist comment, before later returning to complete the match.
Mouctar Diakhaby reacted furiously after a first-half clash with Cadiz’s Juan Cala and spoke with the referee.
Valencia’s players left the pitch in protest and the club said Diakhaby, 24, “received a racial insult”.
He later asked his team-mates to return and they resumed the game but without Diakhaby, who was substituted.
“We offer our complete backing to Mouctar Diakhaby,” Valencia said.
“The team have held a meeting and decided to continue the game, in order to fight for the honour of the club, but denounce racism of any kind.”
The game was 1-1 at the time, with Kevin Gameiro having equalised after Spanish defender Cala opened the scoring for Cadiz.
Cala, 31, was also substituted at half-time, before Marcos Mauro’s 88th-minute goal gave Cadiz a 2-1 victory.