The 26-year-old excelled under current Liverpool boss Jurgen Klopp at Dortmund until the German international moved to Bayern Munich in 2013.
Despite turning down Liverpool before rejoining Dortmund two years ago, the World Cup winner has admitted that a move to Anfield is not out of the question.
"I decided to leave Bayern and Jurgen Klopp was interested in getting me to Liverpool," Gotze said in the documentary Being Mario Gotze.
"I was also interested in working with him again - it's still existing. He is a world-class coach and that's why it's always an option.
"I decided to join Borussia Dortmund, but it was not a decision against Liverpool or Jurgen Klopp. But on the contrary."