The former Bayern Munich man was recently linked with a return to the Allianz Arena, but the Germany international is refusing to divulge the identity of the interested party
The centre-back last week committed himself to the Bundesliga champions until 2017 but has now admitted that his head was temporarily turned by interest from elsewhere.
"I actually had a tempting offer," Hummels told Express. "But I will not say from whom."
The 23-year-old defender is currently with Germany ahead of their Euro 2012 opener against Portugal on Saturday.
Hummels remains unsure if he will be handed a start in Lviv but explained that he will be 100 per cent if required.
"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."
Hummels also revealed that his colleagues are also in great shape, physically and mentally, ahead of the Portugal clash thanks to national team boss Joachim Low.
"He is very calm and objective," the former Bayern Munich man said of the coach. "He always hits the nail on the head. The training is great. And the quality of the players is also outstanding."
Germany's meeting with Portugal is scheduled to kick off at 20:45CET.