Brendan Rodgers's side booked their place in the fourth round of the League Cup via the shootout after earlier playing out a 2-2 draw, and the Spaniard said that he had never been involved in a contest like the one at Anfield.
He told the club's official website: "When we were watching and taking the penalties, everyone was saying, 'When is someone going to miss?'
"I have never seen so many penalties in my life. We took them really well, and Simon [Mignolet] was good as well. It's not that easy when you put the ball on the grass and see the crowd behind.
"Obviously they are supporting you because we are at home, but I was really nervous. It was the first time I have taken a penalty in a situation like that. I knew where I was going to put the penalty and if the goalkeeper saved it, then it's unlucky."
Suso scored twice in the shootout before Albert Adomah missed the decisive kick.