Diaz was allowed to decide on whether or not he would feature after his father's kidnapping in Colombia.
Jurgen Klopp has confirmed Thiago Alcantara and Stefan Bajcetic are no closer to a return as the trip to Kenilworth Road looms, with Andrew Robertson also absent.
"Thiago is an ongoing thing," he told reporters on Friday. "We cannot put any pressure there as well.
"We expect him to be back in the New Year. Another four weeks, I would say that is realistic. I can't wait to have him back."
Thiago has not played since April while teenage midfielder Bajcetic made a brief return in September having seen his 2022-23 campaign also ended early due to injury.
"With Stefan, it's one of these things where Liverpool have a brilliant player," Klopp noted.
"His quality, potential, everybody can see. What a player. But his body was not ready yet. We have to put the brakes on and wait until it's all fine."
Cody Gakpo and Diogo Jota are competing to start up front with Darwin Nunez and Mohamed Salah with all four attackers in the goals lately.
Starting Liverpool XI: Alisson; Alexander-Arnold, Konate, van Dijk, Gomz; Mac Allister, Szoboszlai, Gravenberch; Jota, Nunez, Salah
Subs: Kelleher, Endo, Diaz, Gakpo, Elliott, Tskimikas, Doak, Quansah
Injuries: Robertson, Bajcetic, Thiago
Time and date: 4.30pm GMT, Sunday November 5, 2023
Venue: Kenilworth Road