Scotland begin their bid to qualify for their first major tournament since 1998 against the world champions at Borussia Dortmund's Signal Iduna Park stadium on September 7.
And although Scotland's first challenge is a difficult one, hopes are high that Gordon Strachan's men can qualify for the tournament in France.
Gordon is back in the fold after impressing for new club Celtic since coming back from a long-term injury.
The 31-year-old goalkeeper – who has made 40 appearances for the national team - did not play a competitive match in over two years due to a knee problem, but has returned to first-team action with the Scottish champions this season.
And his team-mate, 21-year-old midfielder McGregor, also won a call-up after scoring four goals for Celtic in the current campaign.
Gordon is one of three goalkeepers selected, alongside Allan McGregor and David Marshall, while three Derby County players – Chris Martin, Craig Bryson and Craig Forsyth – have also been called up again.
Everton forward Steven Naismith is expected to lead the line as a solo striker in Germany.
"It says a lot about his mentality. We're delighted his back," Strachan said of Gordon's inclusion.
"[Callum McGregor] has worked hard at Notts County and Celtic. He's earned his call-up.
"[Naismith has made] a terrific start to the season with Everton in the Premier League [with] two goals in two games.
"[Playing Germany is] a fantastic experience for the players and the fans. We want to make it a tremendous experience by getting a result."
Scotland squad in full:
Goalkeepers: Craig Gordon (Celtic), David Marshall (Cardiff City), Allan McGregor (Hull City)
Defenders: Christophe Berra (Ipswich Town), Craig Forsyth (Derby County), Gordon Greer (Brighton and Hove Albion), Grant Hanley (Blackburn Rovers), Alan Hutton (Aston Villa), Russell Martin (Norwich City), Andy Robertson (Hull City), Steven Whittaker (Norwich City)
Midfielders: Ikechi Anya (Watford), Barry Bannan (Crystal Palace), Craig Bryson (Derby County), Chris Burke (Nottingham Forest), Graham Dorrans (West Bromwich Albion), Darren Fletcher (Manchester United), Shaun Maloney (Wigan Athletic), James McArthur (Wigan Athletic), Kevin McDonald (Wolverhampton Wanderers), Callum McGregor (Celtic), James Morrison (West Bromwich Albion), Charlie Mulgrew (Celtic)
Forwards: Steven Fletcher (Sunderland), Chris Martin (Derby County), Steven Naismith (Everton)
