“We put in a decent performance and we know we can be better. We’ve got a second leg to put it right.
“They celebrated as if they won the tie after the game. They are coming to Anfield and we know our fans will be there.”
Virgil van Dijk echoed Robertson’s thoughts, insisting Liverpool will be ready to bounce back in the second leg.
He added: “We conceded the goal from the corner, first chance for them, not even a chance. Bit of luck.
“The message at half time was to keep playing. We had the ball most of the game but unfortunately could not create massive opportunities. We still have another 90 minutes to set it right.
“It is the way they play. It is a bit of the Spanish football as well and you have to adapt but we knew it and I feel we handled it pretty well.”
Liverpool will now turn their attention to the Premier League, with the Reds hosting West Ham on Monday evening.