Joachim Low surprisingly omitted the 22-year-old from his final squad that travelled to Russia. The Germans were eventually knocked out at the group stage.
And Sane says the setback will only serve as fuel for him this season.
Sane said: "I am looking forward. It has motivated me too. I still want to be on the pitch playing in a World Cup and I will work harder.
"Of course I was disappointed at the beginning but I tried as soon as possible to leave it behind me and to focus on myself - to get mentally back stronger and to look forward.
"Coming back to preseason with my team, I wanted to have full focus on my team and on next season."