Arsenal and Bayern Munich begin their International Champions Cup campaign on Wednesday night, when they face off in Carson, California. So far this summer, the Gunners’ main focus has been off the field, where fans have grown frustrated with owner Stan Kroenke’s running of the club. Fourteen supporters groups have called for the American to make “new and dynamic appointments” and urged him not to treat Arsenal like a “like an investment vehicle”. The signatories have complained of having “never felt more marginalised” and expressed concerns that a lack of investment will see Arsenal overtaken by more ambitious rivals. Arsenal finished fifth in the Premier League last season, extending its league title drought to 15 years. The Gunners’ only signing so far this summer has been Brazilian teenager Gabriel Martinelli and Arsenal coach Unai Emery has to make do with a modest budget of approximately $50 million as he looks to strengthen his team. It is a fraction of what the likes of Manchester City and Manchester United have already spent and Emery could soon have to look to bolster his defense, with Laurent Koscielny wanting out. The club captain has refused to join his teammates on the U.S. tour…