On Tuesday evening, Chelsea were dumped out of the Carabao Cup by London rivals Arsenal, with a scoreline of 1-0 on the night, and 4-2 on aggregate. 

Just to add serious salt into the wounds, former Blues forward Kai Havertz scored the only goal of the night, doing so with the final kick of the game to put his side into the final. 

So, what went wrong? Let's take a look at why the Blues were unable to progress. 

It felt like it would be a long night at the office as soon as the line-ups were announced, and it was confirmed that captain Reece James was not in the match-day squad. 

Having played only 10 minutes or so in the win over West Ham United, many were expecting James straight back into the starting XI, for the biggest game of the season so far. However, full-time, Liam Rosenior has confirmed the right-back had a small knock and was therefore unavailable for the game. 

Hopefully, that means he is back pretty soon, but even if he is back this weekend, Chelsea dearly missed him in such a crucial game - a huge shame in every sense.

The setup from the start felt weird - playing a 352. Truth be told, Rosenior has got it wrong from the start a few times since taking over, but he has been able to rectify his mistakes in-game before tonight. However, on this occasion, he was not able to. 

When you play a wing-back formation, the wing-backs are the most important players. Tonight, Marc Cucurella and Malo Gusto were disappointing. Sure, they have to take responsibility for their own individual performances, but they need to be platformed as well as possible. 

Some may not want to hear it, but Cucurella has been off the boil for quite a while now. His goal against West Ham went a way to mask his performances, but they have been seriously under par over a fairly lengthy period of time. 

It goes without saying that when you have 14 efforts and don't score, but the finishing was simply terrible. It wasn't a case of "it just won't go in". The shots were horrific. Summed up in stoppage time when Cole Palmer found Enzo Fernandez in a pocket of space, with time to shoot - but he blasted his shot well over the bar.

There is no shame in losing 1-0 to Arsenal. They are top of the Premier League and (technically) the Champions League. But it feels like some individually and collectively, avoidable things happened tonight that could have changed the outcome of the game and tie. 

Then, with it being a rival team, it particularly hurts. Chelsea have not won a domestic trophy since the 2018 FA Cup triumph over Manchester United. That has been far, far too long. 

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