Vinicius Junior (two goals) and Marco Asensio scored a goal in the Spanish capital, and Mohamed Salah scored a goal outside the ground.
“It is always good to have a target outside the ground,” Vinaldom told his club’s website.
“Unfortunately they scored a goal after we scored. I must say it would have been easier if it was 2-1 or 2-2,” he added.
“Now we have to score two goals and make sure that our nets are not shaken. This is not impossible, as we have shown in previous years, but it is difficult,” he said.
About the first leg, he explained, “You saw how we played when we had the ball. It wasn’t good enough.”
“When we got the ball back, we lost it quickly, which is why we had to run a lot and that is why the first half was so strong, heavy and difficult,” he said.
The return match will be held at Anfield next Wednesday.