Loris Karius
It took time for Karius to settle as Liverpool’s starting goalkeeper but he helped the team to a Champion’s League final. They met Real Madrid in the showpiece event but it became a living nightmare for the German. That’s because he made two massive mistakes in a career-defining performance that cost his team dearly (via DW).

First, he inexplicably rolled the ball directly to Madrid’s Karim Benzema. The Frenchman calmly slotted the ball home as Los Blancos took the lead. Later, he mishandled Gareth Bale’s shot and palmed the ball into his net. After the game, tests proved that Karius suffered a concussion during the match, but the career-defining moment still destroyed his career.