The defender revealed that he was asked to play through the pain barrier during games before he eventually succumbed to a number of injuries and missed six matches between January and February.
The England right-back told the club's official website: "It feels good to be back. No player wants to be missing matches through injury. I feel myself again.
"I was playing for a few months with niggling injuries and things that were stopping me from putting in performances that I'm used to. It was a hard time and frustrating but I feel better for it now.
"When people see you playing, they assume you're fit, and then when you don't put in the performances that you are used to, people are wondering why. But it's part and parcel of the game, and you've just got to get through those periods."
The Reds are currently second in the Premier League.