The 25-year-old is reportedly one of Louis van Gaal's main targets, with the incoming United boss keen to bolster his defensive options at Old Trafford.
Hummels, who is currently at the World Cup with Germany, has insisted that a move to United is unlikely to happen this summer.
"I never think about that or talk about it because it is something that isn't important for me right now," the Daily Telegraph quotes Hummels as saying. "Maybe it will be some day, but I don't expect it to be like that this summer."
Hummels scored Germany's second goal in their 4-0 victory over Portugal on Monday.