Outgoing coach Rafael Benitez revealed last week the club will spend £100million on new signings. The Spaniard's replacement, who is expected to be former Blues boss Jose Mourinho, has not been confirmed yet.
When asked about the managerial situation, Cech said: "The earlier he can be here, he can start work on things and not leave it for the last moment. You give the new boss the time to prepare things.
"Every summer is important. If you have a bad summer it can have consequences for the whole season. If you don't get people to rest and to have a very good pre-season, you can start the season chasing. This is not an ideal situation. Every summer at a club is important because you have some changes in the squad. We will have a new manager and have to prepare for the oncoming season."