The Spaniard was limited to just a handful of games last term and spent 10 months on the sidelines through injury.
He returned to competitive action for the Reds in their 3-0 win over Tottenham Hotspur last month and the left-back stated his happiness at being back amongst the squad once more.
He told the club's official website: "I've always appreciated football, I've always loved training and I've always loved playing even more. But now, every time I go into training, I am like a child getting back with the team.
"Last year, I came to train alone all of the time while my teammates were outside. For a long time, I was alone and training in the gym because I was injured.
"Now I am training with my teammates again, I feel like the happiest guy in the world. I want to play - but I am so happy just to be back and training."
Liverpool host Aston Villa on Saturday evening.