Schalke midfielder Leon Goretzka has sustained a stress fracture in his lower leg, amid reports he has agreed to join Barcelona.
The Germany international's contract expires at the end of the season and Catalan publication Mundo Deportivo claim the 22-year-old will move to Camp Nou when that deal runs out.
Goretzka has missed Schalke's last two games but has four goals in nine Bundesliga appearances this season, having impressed significantly in Germany's successful Confederations Cup campaign with three in four.
And he will be unavailable for Saturday's trip to Freiburg as Schalke looked to extend their five-game unbeaten run in all competitions.
"Leon Goretzka will miss the game against Freiburg," coach Dominic Tedesco said.
"He needs time to rest and recuperate. We are confident he will recover quickly."