The Germans go into the match on the back of 14 consecutive competitive victories stretching back to the 2010 World Cup.
Low, however, said the odds-on favourites would need to work hard against a team he called "survival artists" because of what he said was their never-say-die attitude.
"It will be very important to use the few chances we will get with a killer instinct," said the 52-year-old. "We will crash into a granite block with their defence but I am sure we will get out chances if we work hard."
"It will be a tight game because the Greeks are not easy to break apart. They have their own style of play. It is in their blood, a tight defence and strong counter-attacks."
"We keep writing them off but they are always there. They are... survival artists."
Low, who called his team the "small favourites" for the title said they were widely expected to reach the last four.
"Yes, it is clear we are the favourites but knockout matches have a character of their own. Look at what happened to Russia," he said of Greece's surprise 1-0 win over the Russians that eliminated the Group A favourites.
"When the game starts it has absolutely no significance."
Low has a full squad to choose from with midfielder Bastian Schweinsteiger, who has trained less than the other players for the past two days due to some pain in his ankle, back fit.
"Bastian will be ready to play. Today he will also complete the final training."
