BBC Sport https://www.bbc.co.uk/sport/football/64735717 https://ichef.bbci.co.uk/ace/standard/240/cpsprodpb/CB86/production/_128720125_gettyimages-1447770678.jpg Newcastle's Callum Wilson says Loris Karius has "so much to prove" after the 2018 Champions League final "made his career take a nosedive".