Where did Enzo Maresca go wrong in defeat to Aston Villa?

On Saturday evening, Chelsea fell to a 2-1 defeat at home to Aston Villa in the Premier League, despite leading 1-0 at half-time. 

There was a huge difference in the first half and second half performances. You could even say there was a big difference between the first hour and the final half an hour. So, what went wrong?

In the first half, Enzo Maresca's side were completely dominant. The Blues had 71% of the ball, 10 shots, two big chances, and 1.97xG. They didn't allow Villa to have a single shot, of any note. 

As usual, Reece James was tucking into midfield, starting build up and stopping counter attacks. Alejandro Garnacho was providing a serious threat in behind on the left hand side, and things were generally going very well. The visitors were pinned back, and unable to get a foot on the ball. 

The start of the second half was less dominant, but there was still an element of control to the performance. However, after 58 minutes - everything changed. 

With a break in play, Unai Emery made a triple change - Ollie Watkins, Jadon Sancho and Amadou Onana replaced Emi Buendia, Donyell Malen and John McGinn. 

From there, Chelsea just could not cope. Within two minutes, Watkins had already made an impact as he slipped Boubacar Kamara through on goal, with Robert Sanchez coming up with a big save. 

Nevertheless, Villa got their equaliser two minutes later, with Morgan Rogers playing Watkins through on goal, who scored at the second attempt after his initial shot was again saved by Sanchez. 

After that, Emery's side continued to create chances and look the more dangerous side. They would be rewarded six minutes from time, as Watkins headed home a Youri Tielemans corner to complete the turnaround. 

Concerningly, even with the new found game state, Chelsea were still unable to wrestle control of the game, and if anyone was going to score a fourth goal of the game, it would be Villa - who went close with a Lucas Digne free-kick late on. An absolutely terrible final half an hour.

So, what went wrong? The difference in the subs were night and day. We saw the changes that Emery made. Meanwhile, Maresca brought on Malo Gusto for Marc Cucurella, Jamie Gittens for Alejandro Garnacho, Liam Delap for Joao Pedro, and Estevao for Cole Palmer. 

Did any of those subs feel like anything other than making changes for the sake of it. Why does Gusto need to come on for Cucurella? As touched on earlier, Garnacho had been a threat to Villa. He had scored two goals against them this time two years ago too. Gittens replaced him and did absolutely nothing. 

Furthermore, did anyone notice Delap on the pitch? Other than when he picked up yet another card. He touched the ball three times in his 21 minutes on the pitch. A disaster transfer up till now, no two ways about it. 

Although many people wanted Estevao to come onto the pitch, why for Palmer? Ahead of the game, Maresca said the 23-year old was now able to play 90 minutes. Sure, it was not his best game, but Pedro Neto was demonstrably worse, and somehow, someway, played the full 90. 

The Chelsea faithful are desperate to see Palmer and Estevao have the chance to play together, yet it just isn't happening. It is ridiculous that Neto is playing full games despite subpar performances. 

Some may point to the fact that Maresca was in the stands, serving a touchline ban. But those sorts of bans have been going on for years. Managers always communicate with the staff on the touchline. And if he didn't, well that's even more embarrassing than the in game management. 

Truth be told, since the beginning of the year, Palmer has not been the same player. Some have suggested that his first few months under Maresca was muscle memory from Mauricio Pochettino. Since the Italian has got his feet under the table, Chelsea's talisman has struggled under the very rigid and positional style of play. 

Whether starting as a number ten and drifting wide, or starting off the right and drifting inside, it is clear that Palmer operates best off the right hand side, in those half spaces. Yet, he seems to play more in the left hand spaces under Maresca. 

There are a number of criticisms of the manager, but perhaps the biggest red flag of all is his inability to platform a player as good as Chelsea's number ten. It is something that must change quickly if the Blues are to achieve anything this season. 

So, in summary; the in game management, substitutions and lack of platforming for the attackers were undoubtedly what predominantly went wrong for Chelsea yesterday.