So much for Arsenal being one of the elite soccer clubs in Europe. The English team is facing the ignominy of being shut out of continental competition for the first time in 25 years only three weeks after being among the instigators of the controversially closed-off and ultimately ill-fated Super League. A failure to overturn a 2-1 deficit against Villarreal in the Europa League semifinals on Thursday would end Arsenal’s quarter-century run of participating in either the Champions League or UEFA’s secondary club competitions. Such a degrading of status would be ironic considering the planned Super League would have placed Arsenal as one of 12 elite teams in the European game.