After losing Andreas Christensen and Antonio Rudiger to free transfers to Real Madrid and Barcelona, respectively, Thomas Tuchel’s team is lacking in central defense.
The Blues are hoping to sign both Koulibaly and Ake.
Raheem Sterling’s transfer from Manchester City is anticipated to be official in the next 48 hours.
Before his move from City is finalized, the English striker is flying to Los Angeles to join the Chelsea team.
The 27-year-old has agreed to a £50 million five-year contract to join Tuchel’s team.
It is thought that Ake’s prospective return to Stamford Bridge is farther along than Koulibaly’s, which has drawn attention from some Premier League teams.
Having played 40 games for Pep Guardiola’s team, Dutch international Ake, 27, joined City from Bournemouth in August 2020 for £40 million.
Before joining Bournemouth in 2017, he spent five years with Chelsea, including some loan transfers.
Koulibaly, the captain of Senegal, is a 31-year-old who has played 317 times for Napoli in Italy’s premier division since joining the team in 2014.
Sterling may be eligible to participate in Chelsea’s first tour game against Club America on Saturday in Las Vegas while the team is in training at the University of California, Los Angeles (UCLA).
On Wednesday, July 20, Tuchel’s team plays Charlotte FC in Charlotte before facing Arsenal in Orlando on July 23.
The 2015 Premier League champions City, who paid £49 million to acquire Sterling from Liverpool, still have one year remaining on Sterling’s contract.
In 339 appearances for Pep Guardiola’s team, he has 131 goals.
When the transaction is finalized, Sterling, 77 England caps, will become Chelsea’s first significant acquisition after their acquisition by a group headed by Todd Boehly this summer.