The 23-year-old has refused to divulge the identity of the mystery club, but maintains he was momentarily swayed by the interest shown in him.
"I actually had a tempting offer," Hummels told Express. "But I will not say from whom."
Hummels has been at the heart of a Dortmund defence that has won back-to-back Bundesliga championships for the first time since the mid-90s.
Speculation was mounting that Manchester United were considering a move for the German international before he committed his future to the club.
The colossal centre-back is currently on international duty with Germany at Euro 2012 and his focus has moved beyond his role at club level.
Dortmund sporting director Michael Zorc recently stated his belief that Hummels should be starting for the German national side in Poland and Ukraine this summer.
"The national team coach should know that he can rely on our players, though. And on Mats Hummels in particular, he's Germany's best centre-back," said Zorc.
However, Hummels himself is still unsure whether or not he will start in Lviv, but maintains he is 100 percent committed to the German cause.
"Whether I play or not, I always prepare myself professionally," he stated. "I look at things on YouTube about the opposing players; their strengths and weaknesses."
