Chelsea did not have the balance right and were too easy to out-fox. The formation is good in games Chelsea dominate but at times it doesn’t work quite so well.
Nemanja Matc is almost flawless as the most defensive midfielder but with Cesc Fabregas next to him and Oscar in front of him it doesn’t always work. The two latter players have tailed off somewhat and this is telling. Ramires is also not a good back-up for any player listed. Chelsea need to go out in the summer and sign a great midfielder who is tailor made to this two man pivot. They also need to adapt and probably play Fabregas as a no.10, not as a no.4.
Fabregas moves out of the two man pivot too much and also isn’t that mobile to chase and press (this has been compounded by clear fatigue in his game since January). Thus, giving Matic a new partner and pushing Fabregas forward might be the solution. Fabregas can then drop into the centre of the midfield to make it a midfield trio. Oscar could be rotated in and out. The trio of Fabregas-Matic-Oscar is just not really working.
In recent weeks the midfield battle has been one Chelsea have been losing. Despite a lot of expensive talent, they haven’t been bossing games, they’ve been second best in this area. As noted Fabregas’ decline has been a huge factor in this. It’s not so much the 4-2-3-1 as a system that is to blame but more the personnel. Chelsea don’t have any specialist midfielders for the two man pivot barring Matic. They also lack the control over games. This is a concern and Jose Mourinho might need to start transitioning to a new system, perhaps one that involves Fabregas a hybrid between a no.10 and a no.8, with a new partner for Matic. For now this lack of control cost Chelsea in Europe.