Chelsea want to bring Juventus centre-back Matthijs de Ligt to Stamford Bridge this summer, according to reports.
Todd Boehly completed his takeover of the Blues at the end of May, and the club is now ready to step up its transfer activity.
Chelsea have been heavily linked with Raheem Sterling and Raphinha as Thomas Tuchel seeks to bolster his attacking options ahead of his second full season at the helm.
He will also be keen to secure replacements for Antonio Rudiger and Andreas Christensen, who have joined Real Madrid and Barcelona respectively.
Cesar Azpilicueta could yet follow his fellow defenders through the Stamford Bridge exit door, leaving Chelsea severely short of options at the back.
The Chelsea squad is due to return for pre-season training on July 2 and Tuchel will hope to have added a couple of new faces to the ranks before then.
According to Sky Italia, De Ligt has emerged as a leading transfer target for the west London outfit.
However, Chelsea would probably need to break the world-record fee for a defender - £80m, paid by Manchester United for Harry Maguire - to land the Netherlands international.
That is because De Ligt's contract contains a release clause of £103m, and Juventus will only entertain offers in that ballpark.
Chelsea might not necessarily need to pay a three-figure sum for the Dutchman, but they would have to surpass the fee United paid for Maguire.
Given that Tuchel also wants to strengthen other areas of his squad, he may have to find a cheaper alternative to De Ligt.
Jules Kounde of Sevilla is a long-term target and Chelsea could renew their interest in the Frenchman if a deal for De Ligt proves too difficult.
Villarreal stopper Pau Torres is another player who has been linked with a move to Stamford Bridge.
Chelsea will begin the new Premier League season against Everton on August 6.
