Jürgen Klopp’s side need to overturn a 3-0 deficit from the first leg at Camp Nou in order to reach the final in Madrid.
But with expectations tempered and a rousing atmosphere inside Anfield, Robertson insists the seemingly impropable could still happen against the Spanish champions.
Asked by Liverpoolfc.com what the approach will be, the Scot said: “Different, but I think it would be daft if we went completely gung-ho because with the players they’ve got, they can pick us off from time to time.
“I think we had more than three opportunities at the Nou Camp and we played a good game.
“Of course there’s going to be times where we need to take a wee bit more risks going forward and taking a few more chances. If we do that then you never know.
“If we can put them under pressure and get the first goal then we’ll see how they react because we know the fans will react positively with us and they can hopefully have an impact on them.
“Let’s just see what happens. We have no real pressure on us now, nobody expects us to do anything. But if we can then it will one of the greatest comebacks.”