Valencia have lost an appeal over a disallowed goal in their youth side's penalty-shootout defeat to Chelsea on February 23.
Chelsea progressed into the quarter-finals of the UEFA Youth League thanks to a 5-4 win on penalties after the match ended 1-1 in normal time.
Alberto Gil's effort from the spot crossed the line before bouncing clear, but the referee wrongly ruled it out.
First-team manager Gary Neville described the decision as "scandalous", but UEFA has not reversed the referee's call.
In response to the ruling, Valencia released a statement, which read: "The club regrets the decision taken by the UEFA. We wish to encourage our young players to continue to be motivated and believe in the fair play of football."
Chelsea tweeted: "TV replays show that Valencia's first penalty in the shoot out did cross the line but it was not given by the officials."
At the weekend, the senior team were beaten 3-0 by Athletic Bilbao at the Mestalla.
