Di Matteo's predecessor Andre Villas-Boas was sacked after his attempted changes failed to have the desired effect, and the Italian is determined not to make the same mistake.
"There won't be radical changes," said Di Matteo.
"Certainly, with the influence of the new players once they are integrated, they will be a bit different because they have different characteristics and abilities. I know we need to win games as well. But I don't think you can expect a completely different Chelsea overnight.
"The majority of the team are still here and, with those players, the club have been very successful already."
Chelsea face league champions Manchester City in the Community Shield tomorrow before travelling to Wigan for their opening Premier League match a week later.