Chelsea's discipline issue
Pedro Neto's dismissal in the second half once again exposed Chelsea's serious disciplinary issue this season. That was their seventh red card in the Premier League - an alarming number for a team competing for the top 4.
The foul on Gabriel Martinelli deserved to be the second yellow card, but what makes the situation unacceptable lies in the context. Neto just received the first yellow card for reacting to the referee less than 3 minutes ago. When Chelsea was leading 2-1 and needed all forces to nurture the hope of equalizing, that lack of restraint action was no different from shooting himself in the foot.
This issue is not new. This season, every time Chelsea loses a player, they almost collapse. They have lost to Manchester United, Fulham and Brighton in red card matches. Before the match against Arsenal, The Blues played a total of 330 minutes in the Premier League with only 10 players - equivalent to nearly 4 full matches.

It is not surprising that they only won one of those matches, against Nottingham Forest. Most of the rest were times they dropped points or went empty-handed.
The consequence of Neto's red card will extend to the key match at Aston Villa in the middle of the week, when he will be suspended. In the context that Chelsea is directly competing for a Champions League spot, this lack of discipline may cost the whole season.
Statistics make things even worse. In the Premier League era, only Sunderland in the 2009-2010 season and Leicester City in the 1994-1995 season had more different players receiving red cards in one season than Chelsea currently.
In the decisive stage of the season, Chelsea's problem is not only tactics or form, but also the ability to keep a cool head. And that is the most dangerous thing.
Chelsea's Champions League hopes in danger
The fact that England leads the UEFA national goal difference rankings almost guarantees that the Premier League will have five Champions League spots next season. But paradoxically, at the right time when the door is wider, Chelsea is struggling to face the risk of being left behind.
The recent defeat makes coach Liam Rosenior's team continue to be stuck outside the top 5. They are only 3 points behind Liverpool - who are currently in fifth place - but the upcoming schedule is really worrying.

Chelsea will travel to Villa Park to meet Aston Villa, just 24 hours after Liverpool visits Wolves. If Liverpool wins all 3 points and Chelsea slips away, the gap could be significantly widened. In the short race as it is now, every point is vital.
Villa's recent form is not really stable, which gives Chelsea some hope. However, that instability also makes the match more unpredictable. Villa is still a direct opponent for a spot in the top 5, and this can be considered a true 6-point match.
If they win at Villa Park, The Blues will not only narrow the gap with Villa itself but also put back pressure on Liverpool. Conversely, an unfavorable result could leave them behind in the context that Man United and Liverpool are both maintaining high form.
The opportunity to participate in the Champions League is wider than ever for English teams. But with Chelsea, this week can decide whether they are still in the race or start being eliminated.