By ESPNSTAR.com staff
Barca missed several good chances during the match and only managed to collect all three points after a superb strike from defender Adriano.
"Our quality will improve," Vilanova said on the Barcelona website.
"We have to get better but our level of play will improve"
However, Vilanova was keen to highlight that his side are the only team which have won all three of their games to start La Liga this season.
"Winning nine out on nine points is very important," he said.
Barca midfielder Cesc Fabregas was guilty of missing two good chances against Valencia but Vilanova was happy enough with the ex-Arsenal captain's contribution.
"In general, he had a great match," he said.
Speaking to his followers on Twitter, Fabregas conceded Sunday's game was a "difficult match".