Against West Ham on Tuesday, Arsenal stuck with the 4 at the back system that has seen them now keep 3 clean sheets on the spin.
The move, which happened before the bore draw against West Ham in the league and was kept for the 1-0 win over Newcastle, was also rolled out to the cup team for the 1-0 win over West Ham.
Whilst the move does seem to have shored us up at the back, it is also a huge positive for rob Holding and Calum Chambers.
The move to 3 at the back never really suited the English pair.
Despite the theory being that 3 at the back would mean more of a chance for central defenders to get a game, Nacho Monreal was played on the left hand side. This meant that the natural centre backs – Koscileny, Mustafi, Mertesacker, Chambers & Holding – were still fighting for just one place.
Chambers would have been a natural on the right hand side of the 3, but struggled for game time. And when he did play in the cup team, he often found himself at wing back.
Meanwhile, Rob Holding found himself out of position.
Holding is a dominating figure who should have been played in the middle of the 3, but when playing in the first team, he often found himself on the left or right. Then in the cup team, Mertesacker was the middle man so he found himself on the left of the 3. An unnatural position.
Against West Ham in the League Cup, Arsenal played Chambers and Holding as a defensive two – and they excelled.
We were not up against a West Ham reserve team. Many of the players featured the week before. Chambers and Holding had the likes of Javier Hernandez, Andrew Ayew and, for 35 minutes, Andy Carroll to deal with. And they did so brilliantly.
Restricting West Ham to no shots on target, and no corners, highlights the defensive masterclass that Holding and Chambers put on.
They were helped by having Francis Coquelin and Mohamed Elneny ahead of them. Two players who are more defensive than attacking. It was a good all round defensive performance.
Chambers, who has struggled to get a chance and spent last season on loan to Middlesbrough, put in a man of the match performance which showed he is ready to stop up.
Against Liverpool, it will be interesting to see whether Arsene Wenger sticks with Nacho Monreal at centre back, or puts Holding or Chambers in next to Koscielny.
What is for certain is both still have a future at the club.
Both players are still just 22 and, with Mertesacker retiring in the summer, will have an opportunity to put themselves forward as (at a minimum) second choice centre backs for the 2018/19 season.
I would expect us to go big in the summer for a new centre back. I also would not be surprised if either Mustafi or Koscileny leave us. This will leave Holding and Chambers as 3rd and 4th choice centre backs. I am comfortable with that.
The return to 4 at the back is a positive for the pair.