Arsenal face arguably their biggest test in the UEFA Champions League league phase later this week when PSG come to north London. The reigning French champions have been regular competitors in the Champions League in recent years with Luis Enrique’s side looking in good form heading into tomorrow night’s blockbuster tie at the Emirates Stadium. With Arsenal drawing 0-0 with Atalanta in their opening game of the league phase, Mikel Arteta will be itching to get back to winning ways tomorrow night against one of his former sides, with PSG an excellent test for the Gunners. Yet the Ligue 1 giants…