The left-back has told his side not to underestimate their southern neighbours, as he feels they have plenty of quality players in their team
The Borussia Dortmund defender feels the Austrians have a lot of quality in their ranks, and could pose a stern test for the Nationalelf.
"Austria are a very unpleasant team to face," Schmelzer was quoted as saying on the official DFB website.
"They are a tough opponent, especially when you take them on in Vienna, and in particular in front of 60,000 home fans at the Ernst Happel Stadium.
"Austria have developed into a strong footballing nation again. Eight players from their current team ply their trade in the Bundesliga and are regular starters at their respective clubs. That says a lot about the quality they have in their team."
Tuesday's encounter is scheduled to kick off at 20:30CET.