The Royal Blues announced that the 22-year-old is still suffering from a persistent and painful stress reaction in bones in his lower leg. He will undergo further tests this week before a decision is made as to when he can resume training.
Goretzka has struggled with injuries this season and was out of action for several days in the summer due to a thigh strain, while he has already missed four league games due to this most recent issue.
The Germany international returned to action as a substitute for Weston McKennie in the 4-4 draw with Borussia Dortmund on Matchday 13, and also started on the bench in his side's 2-2 stalemate with Cologne last weekend, with coach Domenico Tedesco eager to ease him back in gently. McKennie is expected to start in midfield again this weekend in Goretzka's place.
Watch: Highlights of Schalke's draw with Cologne