Dempster, who will be a free agent after the season, is scheduled to make his first start for the Rangers on Thursday.
"My focus right now is just to go down to Texas and do the best I can down there and hopefully win a World Series," Dempster said Wednesday on "The Waddle & Silvy Show" on ESPN 1000. "All my focus and goals are going to be on that and after that we'll see where being a free agent takes me. But I'm open to anything. I don't close doors on any situation.
"And I definitely don't close doors on possibly coming back to the Cubs. It was just an unbelievable nine years of my career and of my life. It's been more than just a baseball team to me. It's been a city and a way of life."