The playmaker endured a fractured season with the Reds due to injury and last played top-flight football in March when he limped off against Watford with a back strain.
Can's hopes of representing his country in next month's Russia finals have now been ended, while he is also thought to be a doubt for the May 26 UEFA Champions League final against holders Real Madrid.
Germany's 27-man provisional World Cup squad:
Goalkeepers: Manuel Neuer (Bayern Munich), Marc-Andre ter Stegen (Barcelona), Bernd Leno (Bayer Leverkusen), Kevin Trapp (Paris Saint-Germain)
Defenders: Mats Hummels (Bayern Munich), Jerome Boateng (Bayern Munich), Joshua Kimmich (Bayern Munich), Jonas Hector (Cologne), Marvin Plattenhardt (Hertha Berlin), Jonathan Tah (Bayer Leverkusen), Matthias Ginter (Borussia Monchengladbach), Niklas Sule (Bayern Munich), Antonio Rudiger (Chelsea)
Midfielders: Toni Kroos (Real Madrid), Mesut Ozil (Arsenal), Sami Khedira (Juventus), Thomas Muller (Bayern Munich), Sebastian Rudy (Bayern Munich), Marco Reus (Borussia Dortmund), Leon Goretzka (Schalke), Leroy Sane (Manchester City), Julian Draxler (Paris Saint-Germain), Ilkay Gundogan (Manchester City), Julian Brandt (Bayer Leverkusen)
Forwards: Timo Werner (RB Leipzig), Mario Gomez (Stuttgart), Nils Petersen (Freiburg)