Hertha Berlin midfielder Florian Kringe faces a spell on the sidelines after sustaining a foot injury during the 2-1 defeat at Mainz.
Kringe, who is on a one-year loan switch from Borussia Dortmund, has had scans on the foot which have confirmed he sustained a fractured which will keep him out of action for two months.
"I was extremely happy to get first-team action again after such a long time and now this has happened,” Kringe told Bild. “I'm very disappointed and feel really sad.”
Schalke midfielder Jermaine Jones has suffered a setback in his recovery from a shin injury.
The 27-year-old had surgery on the problem in June but is still some way short of full fitness.
It had initially been hoped that Jones would have been able to feature in last month's season-opener at Nurnberg.
Coach Felix Magath told Bild: "Jermaine possibly needs to undergo surgery again. We will make a decision about that later this week.”Reuse content