Schalke forward Sebastian Polter could face months on the sidelines with a suspected severe knee injury, the Bundesliga bottom club said on Sunday. Polter was substituted early in Saturday’s friendly against Swiss team Zurich at their winter break training camp in Turkey and then taken to hospital, where cruciate ligament damage was diagnosed. “An MRI scan has shown that Sebastian Polter suffered a suspected cruciate ligament injury in yesterday’s draw with FC Zürich. The 31-year-old will return to Germany later today for further examinations,” Schalke tweeted. Should the ligament be ruptured …