Barca were held by Valencia on Sunday night.
Garay's second minute opener was cancelled out by Messi's equaliser.
Barcelona midfield star Sergio Busquets says he knows the reason why they didn't seal a win over Valencia.
Lionel Messi produced a moment of magic with a 25-yard strike after Ezequiel Garay put Valencia in front at the Mestalla stadium, but it wasn't enough to seal a come-back for the Catalan club.
"I think we were superior and dominated the game in all but one matter, we lacked more clear chances," the midfielder said as Marca reported.
"It was difficult to play against Valencia having gone ahead so early and closing up, letting us play."
Busquets believes Valencia's early goal (in the second minute of the game) was down to luck.
The Spaniard said: "We had a bit of bad luck with the goal, I think the team played well in the first half.
"Leo's goal helped us to be more calm, maybe they would have opened up more, but it wasn't to be."
He added: "It's a very equal league."
Barcelona play Sevilla - who are at the top of the La Liga table - next at the Camp Nou after the international break.