Arsenal forward Kai Havertz is the next player to miss Germany’s upcoming Nation’s League matches against Bosnia-Herzegovina and the Netherlands, with Jonathan Burkardt of Mainz getting a first call-up in his place. The German Football Federation said on Sunday that Havertz had to withdraw with knee problems. Coach Julian Nagelsmann is also without Bayern Munich’s Jamal Musiala and West Ham United striker Niclas Füllkrug due to injuries for the games on Friday in Zenica and three days later in Munich. In addition, goalkeeper Marc-André ter Stegen is out for many months with a severe knee injur…