Germany face Portugal in their FIFA World Cup opener, kicking off Group G that also contains Ghana and the United States.
And Low expects his Germany side to face a tough challenge in getting their campaign under way.
He said: "We're up against a side who are right behind us in the world rankings, and they are the world champions when it comes to the counter-attack.
"Look at the class they have got - Portugal are definitely tough opponents.
"They have always gone a very long way in tournaments, reaching the semis in 2006, and the semis in the last European Championships when they were just one penalty kick short of sending Spain home.
"You could see Portugal as a finalist, with the likes of (Joao) Moutinho, Nani and Ronaldo up front, then (Bruno) Alves, Pepe and (Fabio) Coentrao all experienced guys at the back.
"They all play at the highest level and there is no other side in the world who know how to defend while preparing their next attacks the way Portugal do."
With his primary focus on Ballon d'Or winner Ronaldo, Low has singled out Boateng as his main defensive asset.
"He does play a role who can keep Ronaldo in check, and Jerome Boateng has done that in the past," Low said.
"So too has Lahm so together they will deal with him.
"You cannot let him out of your sight, literally. You've always got to ask 'what's Ronaldo doing, where is Ronaldo?'.
"Ronaldo and Nani seem to be drifting into no-man's land, then the ball is suddenly there at their feet and they are ready to attack you."
