Barcelona and Germany goalkeeper Marc-André ter Stegen faces months on the sidelines after the Spanish top club confirmed on Monday that he has suffered a severe knee injury and underwent surgery. “Tests carried out on the first team player Marc ter Stegen confirm that he has a complete rupture of the patella tendon in his right knee,” Barca said on their website. The team said later that the surgery had been “successful” and that “his recovery will dictate his return.” Spanish news reports said that ter Stegen could be sidelined for at least eight months and could miss the rest of the season….