The Blues have brought in three players so far this summer, with N’Golo Kante, Michy Batshuayi and Eduardo all joining the club, and they are closing in on the signing of left-back Marcos Alonso from Fiorentina.
Chelsea have agreed terms with former defender David Luiz as Antonio Conte seeks to bolster his defensive options.
The Brazilian left the Blues in 2014 to sign for French champions PSG for a fee of £50 million.
PSG recouped a significant amount having agreed £32 million with Chelsea.