The Liga outfit looked on course to be out of contention altogether after conceding two goals without reply in the first half, until Adil Rami's late strike and Zlatan Ibrahimovic's red card gave the home side a fighting chance in the second leg.
"It's a bad result for us but we have hope. We knew they had quality up front and they showed that," Canales told reporters after the game. "There is still a lot left in this tie and – even though we know it will be difficult – we will look to score early over there to give ourselves a chance."
Valencia coach Ernesto Valverde also spoke about the challenge his side overturning a first-leg defeat.
"We have to recognize that our opponent is a great team with great players and they have shown their strength," Valverde said. "In the end we managed to score that goal and that gives us some hope but we know that the return [fixture] will be difficult."