Borussia Dortmund goalkeeper Gregor Kobel will miss Saturday’s Bundesliga match at Mainz with his hip problem but will join up with Switzerland afterwards. “He’s very professional and has good people around him,” Dortmund coach Nuri Sahin told a news conference on Friday. “I have complete faith in my players and also in the Swiss national team.” Alexander Meyer will again deputize in Mainz. “Greg hasn’t trained with the team again yet, so we won’t be taking any risks. He’ll be back against Freiburg (on November 23),” Sahin added. Whether he is fit to play for Switzerland in the Nations League …