Schalke 04 defender Sead Kolasinac could miss up to six weeks of the season with a hamstring injury.
Kolasinac was on the road to recovery from a thigh injury, but the latest setback will see his return delayed until early October.
The player was unable to help his side in their Champions League qualifier on Wednesday night and will also be out of action when the team lines up for the tournament or the Europa League.
Kolasinac joined Schalke in 2011 and has been capped up to Germany Under-20 level.
