Arsenal are set to host Bayer Leverkusen in the Emirates Cup in one of two friendly games before the Premier League season starts, but they are already facing problems. Takehiro Tomiyasu looks set to miss the game as he continues yet another injury absence after picking up a problem before Arsenal’s USA pre-season tour. New signing Riccardo Calafiori may be available, but Mikel Arteta has previously hinted that he wants to ease him in slowly. Oleksandr Zinchenko continued to disappoint in defensive situations in Arsenal’s friendly defeat to Liverpool, whilst Jakub Kiwior has been linked with a…