Chelsea are currently not doing well because the strategy they are using has failed to lead them to victory. It can be seen that in their last game they did not manage to get a win. If Chelsea already have competent players and a good strategy, then it will be easy for them to win, so what needs to be corrected is the strategy they use, and teamwork must also be considered.
It could be that Chelsea's mistake lies in the strategy or the way they face their opponents, but in the second match of the season Chelsea faced a team that is not weak so that factor must also be seen in the defeat that Chelsea got in their second match of the season. In addition, Chelsea's young players must also be trained to be better by the Chelsea coach so that they can become a good mainstay for the Chelsea team this season.
Pochettino hasn't got the right mix of players in his squad. Chelsea are still struggling in their first two matches. even against West Ham, Chelsea conceded 3 goals.
Pochettino made Chelsea's game more interesting in midfield. but there are no good options up front. balls that are passed forward are always raw and only result in non-goal opportunities.
maybe news regarding them having to include Lukaku in the team could be a good option for Pochettino. I'm sure he knows exactly what his team is lacking at the moment.