Cape Town - New Chelsea manager Maurizio Sarri has said it could take up to three months before his players are able to perform to their potential.
The Italian, 59, said that having many of his squad unavailable following the World Cup has made it more difficult for him to shape the team in his mould.
"I am very happy I can work with all my players for the first time tomorrow (Wednesday)," he said after Tuesday’s penalty shootout win over Lyon at Stamford Bridge.
"Potentially we can become, in two or three months, a very good team."
Chelsea start their Premier League campaign at Huddersfield Town on Saturday, a game that Sarri said has probably come too soon.
One player who may not be in training is goalkeeper Thibaut Courtois.
The keeper missed training for the second day in a row on Tuesday as he tries to engineer a move to Real Madrid.
Reports said that Chelsea staff are unsure when the Belgian star will return.
On Friday, Sarri said: "At the moment Courtois is the goalkeeper of Chelsea. I don't know in the future. It depends on the club, it depends especially on him, but I hope Courtois will be our goalkeeper."
The Blues are reportedly lining up Athletic Bilbao goalkeeper Kepa Arrizabalaga as a replacement for Courtois.
Sky Sports reported that the 23-year-old Spain international would cost Chelsea around £70 million, beating the £65 million world record fee Liverpool paid for Alisson last month.
Stoke's Jack Butland is another keeper that Chelsea have been keeping tabs on.