Chelsea will make a £30 million ($39.7 million) bid to AC Milan for Alessio Romagnoli.
Antonio Conte is trying to add depth at center back.
The Serie A club are desperate to hold on to the 21-year-old Italy under-21 international but could be tempted to sell this summer if the current owner, Silvio Berlusconi, as well as the future owners, Haixa Capital, who will take over the club in November, believe they can get an adequate replacement for Romagnoli before the window closes.
Conte is keen to sign a defender, a striker and a reserve goalkeeper before the window shuts next week and he sees Romagnoli as a long-term replacement for John Terry.