"Last season was disappointing and we know we have to do better," the German midfielder told the club's official site. "The run we went on in the middle of the season was very poor and we can't afford for that to happen again.
"We are working hard during pre-season to make sure we are right for the new season. We don't want a repeat of that bad spell last season and I am confident it won't happen. There's a real determination among the players to make this season a good one for everyone at Liverpool."
