Vertonghen said: "During all those months on the sidelines, I had time to reflect. I quickly came to the conclusion that I wouldn't be able to play a full year at the level I wanted. I constantly suffer from ankle pain, so the decision was quite easy to make.
"I've seen about 10 specialists this year who assured me the pain would go away. But the pain is daily, and just walking up the stadium stairs hurts. I have to warm up for a very long time before I can play.
"I take painkillers and have had several injections, but I'm not a fan of that kind of shock treatment. I don't want to be dependent on painkillers. I feel like I'll still be welcome at every club I've played for, and that makes me proud, as does the fact that I've been able to discover many different countries and cultures."