Bayern Munich board member Michael Diederich has criticized Bundesliga and German Cup champions Bayer Leverkusen, and others, for not going abroad in the pre-season. Bayern travel to South Korea on Wednesday, Borussia Dortmund are in the United States, and some other Bundesliga clubs are also abroad. Leverkusen are among the clubs not travelling and currently hold a training camp in the Black Forest. Diederich, responsible for finances at the record Bundesliga champions Munich, said it would have been good for the whole league if Leverkusen had travelled as well, and called for a bigger effort…