Enzo Maresca is keen for Chelsea to a sign a centre-back to cover the absence of the injured Levi Colwill.
England international Colwill is set to miss most of the new season after suffering an anterior cruciate ligament injury in training.
Tosin Adarabioyo and Trevoh Chalobah are poised to start in central defence at home to London rivals Crystal Palace in the Blues' Premier League opener on Sunday.
Chelsea manager Maresca, however, has doubts over whether he can replace the 22-year-old Colwill, a key figure at Stamford Bridge, from within his current squad and has been linked with a move for Antonio Silva of Benfica.
"You know how important Levi has been for us last season, for the way we want to play," Maresca told reporters on Friday.
"We said many times that we are able to create chances and to attack in the right way if we are able to build in the right way. Levi was a huge part of our build-up and now he's out.
"We are trying to find a solution internally, but the club know exactly what I think and we'll see what happens."
The Italian boss added: "I think we need a central defender. We are looking for an internal solution but as I said, the club know exactly what I think.
"We have a fantastic squad. We are happy with the squad. we are, no doubt. But we said many times that when the transfer window is open, anything can happen."
Liverpool manager Arne Slot has tipped Chelsea as title contenders, having also said he expected the west Londoners to beat his side to the Premier League trophy last season.
Chelsea finished fourth last term, 15 points behind champions Liverpool, and Maresca was adamant he had no interest in any so-called 'mind games' from rival managers.
"I don't pay attention to what the other people say about us," he said. "Also because it's easy to say that more clubs are involved. I don't like to play this kind of game.
"I like to be focused on players, try to improve and then what they say, they can say what they want."
Chelsea have just returned to pre-season training following their triumphant World Club Cup campaign.
"We guess we are ready," said Maresca. "It has been quite a short break, but we will try to be ready.
"Unfortunately we don't have the answer, because it's something new."