In his first four matches with Chelsea, Thomas Tuchel has had one very rigid base and a much more fluid attacking unit. The base has always been three center backs and “double sixes”. This allows for a very stable unit of players that can almost always outnumber the opponent playing out from the back as well as stall counters long enough for reinforcements.
The remaining five is where he has experimented the most. The use of wingbacks has stayed the same (and indeed, is little different than how Frank Lampard used the fullbacks to create width), but the overall setup is more fluid. It is also where Tuchel has made the most adjustments for the opponent. In his first match, it was much more of a 3-4-2-1 with the inside forwards both staying below the striker. After that, with the introduction of Mason Mount, it morphed into more of a 3-4-1-2 with Mount acting as a 10 in some matches and a false nine in others as the inside forwards tucked in even further, almost becoming strikers.
At the moment, this 3-4-1-2 system with Mount as a 10/false nine seems to be Tuchel’s main plan. But this match against Barnsley offers him an opportunity not only to rotate and get a look at different players, but to tweak his tactics even further. How might he shake it up?
The most obvious switch would be to a back four with the only question being how it shapes up ahead of the defense. At Paris Saint-Germain, Tuchel often used a 4-2-2-2 and 4-3-3 in addition to his usage of back three formations. Chelsea is obviously well versed in 4-3-3 this season and in the last FA Cup match they did use a 4-2-2-2 as well. Which Tuchel might consider depends upon Timo Werner and the midfielders available. It is highly unlikely that Tuchel goes two up top without Werner and the German could use the rest even more than he could use a moral boosting opponent. Midfield will be a manner of finding three fit midfielders to rest Jorginho and Mateo Kovacic. If N’Golo Kante, Kai Havertz, and Billy Gilmour are all fit they could solve that issue.
There is also the happy medium between the two and go 4-2-3-1. The 4-2-3-1 can easily shift between a formation with two strikers and one with three midfielders if the right players are present. Havertz could be that player as he can fully blur the line between eight, 10, and 9 if given a free enough role.
Or, if Tuchel wants to get even more complicated while finding a happy medium, he can use a half back. This was a role he often played Marquinhos in. On paper, he would be one of the double sixes in the 4-2-3-1. In practice, he could drop into defense to form a back three if needed or he could become a lone holding midfielder if the 10 dropped into an eight position.
Chelsea has frequently done something similar in possession under both Maurizio Sarri and Lampard (often with Jorginho, occasionally with Kovacic) but the difference here is that it would be a legitimate formation change and not just an adjustment to a phase of play. This role seems tailor made for Andreas Christensen given his time as a holding midfielder for the national team and the simple fact that he always seems to do his best with two other centerbacks on the pitch.
There are two wild cards for that role too in Cesar Azpilicueta and Reece James. Azpilicueta in midfield has long been one of the avant-garde ideas for using the Spaniard. James, meanwhile, played in midfield a ton towards the end of his time at Wigan. Either player in midfield surely requires the other to start as well which is a drawback for sure, but Chelsea could be very dangerous with Azpilicueta, James, and perhaps Callum Hudson-Odoi all on the pitch together. Who gets marked? Who needs to be watched for a run? Who will make a cross? The answer is all three which means they will always be able to pull something off or they’ll be marked out, which will just open up other players to get through.
Chelsea needs to beat Barnsley primarily because it would be an embarrassment not to, but Tuchel can still afford to mix it up and try new things. With little training time and having joined preseason, he will get few other chances to experiment as much as he can against Barnsley.