Chelsea want to sign a midfielder and a forward before the transfer window closes; Thomas Tuchel has already spent £268m this summer on players, including Wesley Fofana, Marc Cucurella, Raheem Sterling and Kalidou Koulibaly
Chelsea have made a £43m bid for Ajax midfielder Edson Alvarez.
The club still want to sign a forward and midfielder before the transfer window closes.
Head coach Thomas Tuchel has already spent £268m this summer on players, including Wesley Fofana, Marc Cucurella, Raheem Sterling and Kalidou Koulibaly.
Ajax have already sold key players Ryan Gravenberch, Lisandro Martinez and Sebastien Haller this summer with Antony set to finalise his move to Manchester United this week.
The Dutch champions are projected to make in the region of £180m from sales in this window, and are under no pressure to allow Mexico international Alvarez to leave.
The transfer window in the Netherlands also shuts 24 hours earlier than most of Europe this summer due to an administrative error made by the nation's football governing body, KNVB.
Chelsea completed the signing of centre-back Wesley Fofana from Leicester in a deal worth up to £75m on Wednesday.
Chelsea will pay an initial £70m, with a further £5m possible in add-ons, and Fofana has signed a seven-year contract with the club.
Leicester and Chelsea agreed a fee for Fofana on Saturday, with the defender flying to the USA on Monday for his medical.
Fofana said: "The two last days have been really big days for me and I'm very happy. I trained this morning with the team and it's a dream for me. I'm very excited to start playing games for the fans and the club.
"I'm here to win trophies - the Champions League, Premier League, FA Cup, Carabao Cup, everything. I came here to win and the club is built to win trophies so I'm here to continue that."