The England midfielder confessed that he had been advised to undergo surgery as early as his final season at Dortmund but chose to postpone the procedure to avoid missing major tournaments.
He added: “In my last season at Dortmund, at the beginning, they already told me I had to have surgery on my shoulder after a bad fall. I knew something wasn't right, but it was August-September and the World Cup was in December, so I didn't have the surgery. Then I started to feel good. When I arrived at Madrid, I had no pain.
“Everyone told me I had to have surgery, but it was my first year at Real Madrid and I didn't want to leave the team stranded and be out for three months. After losing the Euro final against Spain, I didn't want that to be my last taste of action for three months, but that would have been the best time to have surgery. I decided to continue for another year and I shouldn't have done it.”