Reus, who missed half of this season through injury, was ruled out of the 2014 World Cup after being injured in Germany's last warm-up match. The group must be whittled down to 23 by June 4, with the tournament starting on June 14.
"Both sides are aware of their responsibilities". The defending World Cup champions are expected to be among the favourites to win the tournament in Russian Federation this year. "He's our captain and we hope that he can go into the tournament 100 percent fit".
Oliver Kahn has raised doubts over Manuel Neuer's chances of playing for Germany at the World Cup.
Freiburg striker Nils Petersen earned his first call-up to the national team, ensuring his place in the squad ahead of Bayern Munich forward Sandro Wagner.
"We had to make a decision, and it was made in favour of Gomez and Petersen", Low said. "He has great intelligence in the game and in the second half of the season he was in really good form".
Reus, meanwhile, finally has a chance to play in a World Cup, having returned to form and fitness at Borussia Dortmund since his comeback from injury in February.
Midfielders: Julian Brandt (Bayer Leverkusen), Julian Draxler (Paris Saint-Germain), Leon Goretzka (Schalke), Ilkay Gundogan (Manchester City), Sami Khedira (Juventus), Toni Kroos (Real Madrid), Mesut Oezil (Arsenal), Sebastian Rudy (Bayern Munich).
But manager Joachim Low, who has extended his contract to 2022, names the world-class keeper along with Barcelona's Marc-Andre ter Stegen, Bayer Leverkusen's Bernd Leno and PSG stopper Kevin Trapp.
Germany will face Mexico, Sweden and South Korea in Group F at next month's World Cup in Russian Federation.