Barcelona midfielder Sergio Busquets broke Valencia's hearts on Sunday, smashing home a rebound deep into stoppage time to give the Catalan outfit a 1-0 win at the Mestalla.
Valencia had their chances throughout but Sofiane Feghouli and Alvaro Negredo were both denied by Barca keeper Claudio Bravo before Busquets struck as Nuno Espirito Santo's men suffered back-to-back La Liga defeats.
Despite the loss, Diego Alves opted to remain positive post-game with Valencia fifth in the standings after 13 rounds.
"I think we had our chances as well. I thought it was a really physical game," the 29-year-old Brazilian told television reporters.
"It's a bit of bad luck. The team understood exactly what the gaffer wanted. We managed to cause them quite a bit of damage on the break.
"We prevented them from scoring until the very final, final move of the game. Neymar's header came off my chest and Busquets put it away.
"We had to look on the positive side. It's a really long competition and we want to keep fighting."