"We go into this season with a lot of hope. The World Cup is right in front of us and this is the last stretch," Loew told a news conference.
"The Paraguay game is not a warm-up exercise but a serious test against a South American team."
Loew has seen the backbone of players from Bayern Munich and Borussia Dortmund return after they missed out on a United States tour in May due to the Champions League final.
The Germany coach picked none of the newcomers from that trip two months ago with forward Max Kruse, who stood out on tour, being the biggest absence with Loew opting for the experience of Mario Gomez and 35-year-old veteran Miroslav Klose.
"I am happy that for the first time in five months we have many players with us again who are the foundation of this team," said Loew, still looking for his first title after one final and two semi-final appearances in three major tournaments during his watch.
He will, however, be without midfielders Bastian Schweinsteiger and Mario Goetze, both having only recently recovered from injuries as well as Toni Kroos, expecting the birth of his first child.
Germany are top of their World Cup qualifying group on 16 points from six games, five ahead of Austria whom they play on Sept 6 before travelling to the Faroe Islands four days later. Sweden and Ireland also have 11 points.
"We have an outstanding position in our group and are on an approach flight to Brazil. In September we can take the decisive step. We want to win the group without losing a game," Loew said.
Squad:
Goalkeepers: Manuel Neuer (Bayern Munich), Rene Adler (Hamburg SV)
Defenders: Jerome Boateng (Bayern Munich), Benedikt Hoewedes (Schalke 04), Mats Hummels (Borussia Dortmund), Marcell Jansen (Hamburg SV), Philipp Lahm (Bayern Munich), Per Mertesacker (Arsenal), Marcel Schmelzer (Borussia Dortmund)
Midfielders: Lars Bender (Bayer Leverkusen), Sven Bender (Borussia Dortmund), Julian Draxler (Schalke 04), Ilkay Gundogan (Borussia Dortmund), Sami Khedira (Real Madrid), Thomas Mueller (Bayern Munich) Mesut Ozil (Real Madrid), Lukas Podolski (Arsenal), Marco Reus (Borussia Dortmund), Andre Schuerrle (Chelsea).
Forwards: Miroslav Klose (Lazio), Mario Gomez (Fiorentina)
(Reporting by Karolos Grohmann, editing by Amlan Chakraborty)
