Maurizio Sarri says it could take up to three months for Chelsea to reach top form with his playing style.
The Blues' pre-season preparations have been hindered by the late return of Gary Cahill, Eden Hazard, Michy Batshuayi, N’Golo Kante and Olivier Giroud to training following the World Cup.
Batshuayi was the only recent returnee who did not feature in their 0-0 draw with Lyon in the International Champions Cup on Tuesday, and Sarri feels it is better late than never with their Premier League campaign starting at Huddersfield on Saturday.
"I'm very happy I can work with all my players for the first time [on Wednesday]," said Sarri after Chelsea's 5-4 penalty shootout victory.
"Potentially we can become, in two or three months, a very good team.
"They arrived yesterday or the day before so it was only because I think it’s better to play 25 minutes than to have a session alone with a physical coach.
"They have to work, obviously. I’m very happy and at last I can work with all my players for the first time [together] tomorrow. We have only three days to prepare for the next match and it will be very important for us.
"I think we have to work, but we started to work [together] two days ago. Potentially, in two or three months, we can become a very good team."
Midfielder Jorginho is the only major signing Chelsea have made this summer, but another is expected to follow in Kepa Arrizabalaga - Goal understands the Blues will trigger the goalkeeper's €80 million (£71m/$92m) release clause.
That will free up Thibaut Courtois to complete a move to Real Madrid but Sarri declined to comment on the possible incomings and outgoings at Stamford Bridge.
"I think I’m here just to talk about the match and the first question was about Courtois. I don’t know at this moment, I want to speak with my club and then all together we will decide. If I don’t know anything about Courtois I don’t know anything about Kepa."
Chelsea could give Ruben Loftus-Cheek a spot in the first team this year after his impressive spell at Crystal Palace, and Sarri sees a lot of potential in him.
"He is potentially a great player. He has to improve from the tactical point of view but that’s not a problem," he added. "He’s very young and I think he can be a very useful player for us."