It will take more than one season to see Chelsea back to the form they had at least two or three years ago. I think next season they can only get their game up and running, but no way they can become leaders or make it to the top 4. They can make a few transfers, but I doubt that's what will save them, they need to rebuild most of the team
You cant predict football, to you it may seem it will take Chelsea a long time for them to be that great team again,it can shock you in next season Chelsea can be among the best team in Premier league. If Chelsea is in the hand of the right coach I believe they will do better in next season. Chelsea I have been very poor performance for a long time, Pochettino will try his best to revive the team. You shouldn't expect Chelsea to lead Premier league next season after having a terrible season, I expect them to be in the first four top teams .