Germany goalkeeper Marc-André ter Stegen may have suffered a serious knee injury during Barcelona’s 5-1 win at Villarreal on Sunday. The 32-year-old came down on his right leg following a corner shortly before half-time and immediately fell to the turf. The Barça captain had to be carried off the pitch on a stretcher and was then taken to hospital. A diagnosis had not yet been confirmed but Barca coach Hansi Flick told a news conference: “We’re very happy about the win, but in truth sad because I think it’s a serious injury.” Speaking to DAZN, the former Germany coach added: “We’ll have to wai…