The 52-year-old coach believes that the upcoming match against the Seleccao will go down to the wire, while revealing that he has no plans to double mark Cristiano Ronaldo
Die Mannschaft lock horns with Paulo Bento's side in their opening Euro 2012 match four years after sending the Seleccao packing at the quarter-final stage in the tournament in Austria and Switzerland.
Portugal's back line has been suggested as the team's weakest link, but Low is taking nothing for granted in the build-up to the match.
"For me, Portugal are one of the best technical sides in the world," he said at a press conference. "Pepe and Bruno Alves have international experience and that is why I have to say that this is a different team from the one in 2008.
"I expect an open game and a match on an equal footing. Both teams are willing to win the match.
"We will not speculate, but anticipate. Portugal are able to play very quickly and in a technical way. Cristiano Ronaldo is very good at running deep, so we have to close down the passing lanes.
"We must help each other, but that does not mean that we will have two men marking one specific player.
"We must stand against the players one-on-one, because otherwise there will be free players."
Germany are widely considered as one of the favourites for Euro 2012, but Low is refusing to think beyond Saturday's contest.
"In a tournament, we must think step by step," he explained. "That is why our only focus has to be on the match against Portugal.
"The players are very focused and willing to win. I notice the tension is growing amongst them. The closer it gets to the tournament, the calmer I become.
"My thoughts are becoming clearer. The anticipation is growing at the start of the tournament.
"There are many thoughts, many conversations, but I am glad that it is finally starting."
The 52-year-old coach then confirmed that Philipp Lahm will start at left-back against Portugal, but admitted that he still has doubts about who will play on the other side of the defence.
"Lahm will start on the left side, like he did during the last matches," Low added. "For the national team it is good to have him there.
"On the right side of the defence we have Jerome Boateng, but Lars Bender has made impressive progress and left a good impression during our trainings sessions.
"We will see what we will do for the match against Portugal. "
Lahm also confirmed that he was set to play on the left side of defence, but stated that he would be equally happy to feature at right-back, a berth which he filled for Bayern Munich towards the end of the domestic season.
"The coach sees me on the left. I can switch within a game and play on the left or the right."