The highly rated 23-year-old established himself as a key player for Hoffenheim last season, scoring 11 goals and providing eight assists in his 35 games.
It had been widely reported that Asllani was on the verge of joining RB Leipzig, but that move has since collapsed "due to medical concerns raised by Leipzig."
"Fisnik has made remarkable progress at Hoffenheim," said the club's managing director for sport, Andreas Schicker.
"The fact that this transfer is no longer happening is anything but bad news for us from a sporting perspective. We have complete confidence that Fisnik is capable of performing at the highest level, both physically and on the pitch.
"We stand by our player. Fisnik played a key role in our success last season, completed pre-season to his usual high standard and will rejoin the squad in training next week."