Although the £20 million deal for the Bayern Munich midfielder was not announced until late on Friday afternoon the formalities had already been completed in advance for the Spain international to join the squad if manager Jurgen Klopp requires.
The new recruits must wait for their league debuts for the Blues, with Ziyech still nursing a knee complaint, Chilwell a heel issue and Silva searching for match fitness.
Christian Pulisic is still to shake off a hamstring problem, but striker Timo Werner is fit, having eased past a dead leg picked up at Brighton on Monday.
Liverpool provisional squad: Alisson, Alexander-Arnold, Gomez, Van Dijk, Robertson, Fabinho, Wijnaldum, Henderson, Salah, Firmino, Mane, Adrian, Williams, Matip, Thiago, Milner, Keita, Jones, Origi, Minamino.
Chelsea provisional squad: Kepa, James, Christensen, Zouma, Alonso, Kante, Jorginho, Havertz, Mount, Loftus-Cheek, Werner, Caballero, Rudiger, Azpilicueta, Kovacic, Barkley, Hudson-Odoi, Abraham, Giroud.