Fulham fullback Riether unsure of Cologne plans
He could still be plying his trade back in Germany next campaign.
"Nothing is decided yet," he told German magazine Kicker. "Fulham can activate a clause, and I also have to agree.
"As things stand now, I will return to Cologne in the summer. But I have to consider and talk to both clubs.
"I wanted to become a starter (at Fulham), and I managed to do that. I am proud I have become a fans' favourite. But of course I can still do better, and that's what I am trying to do."