The only goal scored against Antonio Conte's side came following nine changes for the final Group E match against Republic of Ireland, which ended in a 1-0 defeat.
With the Juve quartet reunited at the back for the last-16 meeting with Spain, Italy were back at their best to win 2-0.
While Hummels concedes the Azzurri's solidity at the back has been impressive, he believes Gomez - who has scored two goals in three appearances at Euro 2016 - can cause them problems.
Asked who was better out of himself and Bonucci, the Germany defender responded: "Tough question. I'm very impressed with the Italian defence. Not only Bonucci, but Barzagli and Chiellini, too.
"They're definitely among the strongest central defenders in the world. I hope that after the game I may have had the better match, because Mario will have scored against them.
"In general, it's difficult to answer this type of question. It can change in the space of a few weeks according to form, sometimes luck too. I find both are two good defenders."
Hummels believes fitness will play an important role in the outcome of Saturday's quarter-final in Bordeaux, though he is unsure who will have the upper hand in those terms.
"Physical condition could be crucial. But I'm not able to say which team I think is at an advantage. Unfortunately the Italians are fit, too," he added.
"Of course, it would be nice if we'd have an advantage in fitness, but I don't think so. Desire could be also crucial. But it would be a problem if someone did not bring desire with them."
Indeed, it was Germany's mentality that came into question from their national media following a 2-1 defeat to Italy in the semi-finals of Euro 2012.
"After our loss back in 2012, it was said that the Italians would have wanted it more, because they were singing the national anthem louder than us, according to some newspapers," continued Hummels.
"I don't think you symbolise willingness with that, but it is shown on the field. And in this case we showed our good face in the past."