The 21-year-old goalkeeper had been linked with a move away from the Bundesliga club after playing a big part in their rise to fourth in the table.
He kept a clean sheet in their last match against Borussia Dortmund as they recorded an unexpected victory, before impressing for Germany Under-21s in their victories over Montenegro and the Faroe Islands.
"I guess it is the usual way," he said. "If you have a goalkeeper as we do, many great teams are interested in him.
"This boy has everything, charisma and lots of talent. He is a really good goalkeeper.
"He is very young and I hope he stays with us a little bit longer."
"Right now it is Bundesliga time and the Bundesliga is something completely different," he added. "They [their international players] were away for 10 days and now we are together again to prepare for the match against Hertha Berlin."
