Gerard Pique restored parity for Barca after Loukas Vyntra had opened the scoring for the home side, but the Spanish fixture ended with a share of the spoils in Valencia.
"It's a shame we did not win because we did everything possible to bag the full three points. They closed themselves off at the back and they didn't give us any space," he told reporters at a press conference.
"It's a difficult stadium to play in, but we tried. We did enough to deserve the win, we just lacked a bit of luck."
Barcelona remain top of the table after Atletico Madrid failed to beat Sevilla in the late kickoff on Sunday evening.