The midfielder, who joined the Reds from Southampton for £23m during the summer, featured in yesterday's 1-0 defeat to Aston Villa at Anfield.
The 26-year-old told the Liverpool Echo: "It felt good to get 60 minutes under my belt, but it still can't take away the feeling of a defeat.
"I still feel a little bit rusty but I felt better as the game went on. The lads are down and disappointed and we know we've got to bounce back quickly.
"It's a huge game and a huge honour to play for Liverpool in the Champions League, it's where the club belongs. Having a game on Tuesday is the best thing on the back of a defeat. We've just got to recover well and go again on Tuesday night."