The Georgia international has arrived from Valencia to initially act as Alisson's backup.
Valero, who himself has returned to Liverpool this summer from West Ham, told liverpoolfc.com: “Alisson is the best goalkeeper in the world and he has been at that level for years so for all of us here it’s our job, our responsibility, to keep the standards really high.
“From my side, it’s my responsibility to keep the standards high in the goalkeeping position and we are lucky as a club to have the best goalkeeper in the world with us.
“So, that’s a responsibility but I have been lucky enough to be exposed to these kind of challenges in the past and the target this season is to keep the high standards that have been set by the club for many years.
“And then in Gio we have a goalkeeper who is a younger goalkeeper with huge potential. He is the best young goalkeeper in Europe and I think he’s already showing that he has got what you need to have to be a top goalkeeper in the coming years.
“He’s been very solid and he keeps growing, and he showed that in La Liga with Valencia for all those years. I would say that he is the best goalkeeper of his age.
“I think we are lucky in the club to have the best goalkeeper in the world and the one that is the best of his age. We have a very strong set-up with these two goalkeepers."