The Blues have been active in the transfer market this summer, wrapping up deals for Raheem Sterling, Kalidou Koulibaly, Marc Cucurella, Carney Chukwuemeka and Gabriel Slonina.
However, they have also missed out on a number of transfer targets, with Raphinha, Robert Lewandowski and Jules Kounde all moving to Barcelona.
After the departures of Antonio Rudiger and Andreas Christensen on free transfers, the Blues want to further reinforce their options at centre-back.
The west London club are also targeting a central midfielder and striker, with Armando Broja the only recognised centre-forward in the senior squad.
According to ESPN, Tuchel is keen on bringing in three more players before the transfer window closes.
The Blues boss’ prime targets are Barcelona duo Frenkie de Jong and Pierre-Emerick Aubameyang, as well as Leicester City central defender Wesley Fofana.
Up front, the Blues are light on options up front following the exit of Romelu Lukaku to Inter Milan on loan.
Former Arsenal striker Aubameyang is an option being explored, but the player’s preference is to remain at Camp Nou.
De Jong, a target also of Manchester United, is in the same situation as his Barca teammate Aubameyang in that he wants to stay at the Catalan club.
United have an agreement with Barca in place for De Jong, but Chelsea are said to be willing to match the £73m bid from the Red Devils.
Meanwhile, Leicester have turned down two bids from Chelsea for Fofana as the Foxes are demanding £80million – a world-record fee for a defender.
Asked about bids for Fofana at a press conference on Thursday, Leicester boss Brendan Rodgers said: ‘There was two, but nowhere near what the club would consider.
‘We’re not looking to sell. Naturally if there’s interest from other clubs, that is looked at by the club. He’s a top young defender and there are not too many around his age.’
‘Another year for him at least would be really important for his development,’ Rodgers added.
‘Wesley is quite calm on the situation. He is aware of the interest. He’s just getting on with his work.’
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