I'm afraid Chelsea couldn't start the friendly matches well.

First a draw against Wrexham and now a huge defeat by Celtic, 4-1. Maresca is new around here of course but hopefully he manages to find the right system for the team soon.
It's a setback for Chelsea. They had beaten Wrexham 5-0 last season, but Chelsea drew against them now. A big setback for Chelsea. I know the decision to replace Pochettino with Maresca is very bad. It's still just a pre-season game. But this seems like a bad scoreline no matter what. Also, Chelsea owners Todd Boehly and Beghdad Eghbali bet too much on Maresca.
I'm really nervous about how Maresca managing Chelsea in the Prem. If he doesn't change his tactics, Chelsea will have a terrible season.And again, Maresca can't keep playing without a talented squad.
Because there isn't a long time period left for the season to start officially. Pochettino was sacked for no reason and now they have to experience the same process again. Enzo Maresca will need to adapt to the team to make things better. The worst case scenario would be his not being able to meet the expectations at all. In that case, I presume that Boehly would regret sacking Pochettino while things were getting better actually.
To be honest, Chelsea's pre-season under Maresca is worse than under Pochettino. I think Chelsea is now at a very low point compared to when Pochettino managed them. Maresca's unbalanced squad will be a disaster. Boehly must tell Lampard to be ready as Chelsea's interim manager. I expect Lampard to replace Maresca in the middle of the season.
Cole Palmer has a lot of hard carrying to do this season. His club has been consistently horrendous. Palmer probabl chelsea's hope, and that's pretty much the same like last season.