This setback is a blow to coach Julian Nagelsmann, who had planned to bring in Fullkrug as an injury replacement for Stuttgart striker Jamie Leweling.
Leweling missed the game against Luxembourg with adductor problems, and Nagelsmann was counting on Fullkrug to step in.
However, he received news from West Ham that Fullkrug's injury would keep him sidelined, forcing him to reconsider his plans.