(C)Getty ImagesSoham Mukherjee‘Gutted’ Mikel Arteta reveals the one thing Arsenal were missing to ‘unlock the tie’ against Bayern after Champions League exitMikel ArtetaArsenalBayern Munich vs ArsenalBayern MunichChampions LeagueMikel Arteta admitted that the Arsenal dressing room is "gutted" after their Champions League defeat to Bayern Munich.Article continues belowArticle continues belowArticle continues belowBayern beat Arsenal 3-2 on aggregateArteta admitted Gunners were not at required levelRevealed what his team were missingArticle continues below