Chelsea’s disciplinary nightmare has taken another turn for the worse following their 2-1 defeat to Arsenal at the Emirates Stadium. Winger Pedro Neto, who was already facing a standard suspension for his red card, has now been officially charged by the Football Association for his conduct following the dismissal. The Portuguese international was sent off during a frantic second half as the Blues lost to their London rivals.The incident occurred shortly after Jurrien Timber put the Gunners ahead, with Neto picking up two quick yellow cards that left Liam Rosenior’s side a man down. For the first booking, he was cautioned for dissent while aggressively protesting Arsenal's second goal. And just three minutes later, a cynical foul on Gabriel Martinelli ended his afternoon prematurely, leaving Chelsea to struggle through the closing stages with 10 men on the pitch.The Football Association has moved to punish the winger further, citing both his delay in leaving the field and his choice of language toward match officials. The FA confirmed the news via social media, stating: "Pedro Neto has been charged after being sent off in the 70th minute of the Premier League fixture between Chelsea FC and Arsenal FC on Sunday 1 March. It's alleged that the player acted in an improper manner by failing to leave the pitch promptly; and/or used abusive words towards the match official/s. Pedro Neto has until Monday 9 March to provide a response."This latest development adds to a mounting disciplinary crisis for the Blues, who have now seen nine players sent off across all competitions this season. The lack of composure from a key attacking outlet has drawn significant backlash, with former Blues forward Chris Sutton labelling the winger an "idiot" for failing to keep his cool in such a high-stakes environment.Manager Liam Rosenior is clearly reaching the end of his tether regarding his team's inability to keep 11 players on the pitch. While he defended goalkeeper Robert Sanchez from individual criticism, he was far less forgiving about the red card situation. The manager is desperate to see a change in mentality, noting that Neto has apologised to the group since the incident took place at the Emirates.Speaking on the matter, Rosenior said: "My job is to create a culture of accountability. If you make a mistake, you have to hold your hands up to make sure it never happens again. You need teammates to help you but it comes down to yourself as well. Pedro has apologised to the group. I need to see an improvement in the behaviour now... We are one of the youngest teams in Europe. Sometimes you need to go through experiences to improve. I don't want it to be a learning experience where we fail to achieve what we want to achieve."Add GOAL.com as a preferred source on Google to see more of our reportingThe fallout from the Arsenal game served as a wake-up call for the Blues, who responded with a convincing 4-1 win at Villa Park powered by a Joao Pedro hat-trick. Meanwhile, Neto has officially served his suspension and is eligible to return for the upcoming cup tie, with this selection boost coming at a pivotal moment as Chelsea pause their Premier League campaign to focus on cup competitions. They first host Hollywood-owned Wrexham in the FA Cup fifth round, before traveling to Paris for a blockbuster Champions League round-of-16 first leg against PSG.