On-loan from Barcelona, Ter Stegen faces 1-2 months on the sidelines, so putting his place in Germany's World Cup squad in jeopardy.
In a statement, Ter Stegen declared last night: "Most of you don't know me on a personal level, so I want to share something with you.
"I'm a positive person. I've always had this mindset and I've carried it with me through every challenge I've faced, but this one is proving especially tough for me.
"Last weekend, the worst happened: I got injured during the match. I had just arrived in Girona, where from the very first minute I was treated with so much kindness and warmth. I was really looking forward to being part of the team and helping us achieve our common goal.
"My role has now had to change completely, but my support for the team will not. It's not just a great group of players and coaching staff; it feels like a family, and I've felt their support and closeness from the very beginning.
"As athletes, our greatest joy is competing: training and playing. I have to put all that on hold for several months, as I've decided to have surgery.
"I will return."