The 29-year old German defender is on a season-long loan from FC Cologne and has enjoyed his time so much that he wants to remain at Craven Cottage past this summer.
"I'd like to remain here," he told the club's official website.
"Fulham have an option to buy me and so I think in the next few weeks there will be talks about my future.
"At the moment I can't really say what will happen.
"But I like it here and I'm thankful that Fulham gave me the chance to play in the Premier League."