The blame should be directed to all of their defenders and Maresca. I try to point out some key points here.
Sounds interesting, i think, it's weird to see Chelsea and their position right now, 2 win, 2 lose, 2 draw, and 2 red card, this is really not a good start for them. However, if the loss 1 player became the reason, then the manager must immediately take a decission to set an alternative strategy when they are playing with 10 men because of red cards. If they continue with this strategy, it will be easy for their opponents to beat them. On matchday 7, they face Liverpool, which will be even more difficult for Chelsea to get 3 points. Full preparations and training needed for chelsea.
Yeah, i hope Maresca will come with a solution. Indisciplinary is his club's main problem. It must be sorted out asap to ensure there won't be another red card.
if they get another red card in this game, i will have zero expectation for them to win it. I'm getting so sick and tired with disappointment delivered by them.