The Spanish youngster conceded he is not expecting to find the three points gift-wrapped against the Catalan side and stressed his team will play to win the match
The Mestalla outfit are at the summit of La Liga, with a perfect nine points from three games, and must now defend their position against third-placed Barcelona, who are coming off an 8-0 mauling of Osasuna.
With 15 goals scored to date, Barcelona are topping the league's scoring charts, but Canales has called on his team to go out with a winning mentality.
"We are happy with the work we have been doing," he said at a press conference. "We have not conceded any goals in the last three games.
"We must not be afraid of suffering a heavy defeat, we have to play knowing we can win.
"This will be a tough match, but we will try to win, as always. Barcelona are perhaps the team who have made the least mistakes, but we have to search for them."
Questioned about Real Madrid's 1-0 defeat at Levante, Canales, who is owned by the Bernabeu outfit, gave little importance to the result.
"Any team can beat anyone," he noted. "The league has just started, only three matches have been played.
"I am only focused on my team and on how well we have been doing."