The 23-year-old midfielder remained in Gelsenkirchen overnight. An appearance next weekend at home against Mainz 05 (Saturday, March 15th at 15:30 CET) looks doubtful. TSG's medical department will monitor his development over the next week.
Jens Grahl is also a doubt to make the squad next weekend. The Hoffenheim goalkeeper suffered a muscle tear in his right calf during the final training session ahead of the Schalke match.
Things are looking a little better for David Abraham though. The central defender is back in fitness training following adductor issues. However, it's not yet clear when he will be able to rejoin team training.