Both Liverpool stars missed Tuesday's friendlies against Wacker Innsbruck and Stuttgart
Liverpool boss Jurgen Klopp has admitted it would be a ‘surprise’ if Virgil van Dijk or Joe Gomez were declared fit to face Mainz on Friday.
The defensive duo spent large parts of last season on the sidelines and have spent much of the pre-season tour of Austria working to their own individual programmes.
On Tuesday, both were absent for the two 30-minute matches against Wacker Innsbruck and Stuttgart, which each ended 1-1, and it appears the Mainz encounter will come too soon also.
"It would be a surprise, to me as well," Klopp told LFCTV.
"They have looked really good in training and yesterday was the first day where they did very complex things, usually it is either offensive or defensive and stuff like this.
"We have to get there, step-by-step, but I don't expect them for Friday."