What that teaches us is this, one bad signing can destroy a team season, Xhaka possesses none of the credential Arsenal need his lack of stamina effects his ability to
move up the pitch and distribute the
ball and hence close the opposition down, his poor acceleration put him in at a massive disadvantage in taking on the one on one chase back
toward his
goal, his sluggish tackling causes him to get sent off and his poor positioning allow the opposition plenty of space to exploit, Xhaka overall style of play is going to cause Arsenal huge problems for the foreseeable future.