Hamburger SV’s Nicolai Muller has been ruled out of action for up to seven months with a cruciate knee ligament injury he suffered while celebrating.
The 29-year-old former Mainz 05 winger scored the only goal on eight minutes in Hamburg's win over Augsburg on Saturday.
And while celebrating his effort, Muller fell awkwardly after spinning in the air and tripping over the corner flag.
He was substituted five minutes later, with Hamburg sporting director Jens Todt revealing his shock at the turn of events.
He told the club's official website: "The diagnosis comes as a huge shock to us, it's a big blow at the start of the season and obviously is really tough on Nicolai.
"We wish him all the best for his recovery and, of course, will support him as best we can."
Head coach Markus Gisdol added: "It's bad news. I've never seen anything like it."