Totti played with Salah at Roma.
“The level he is playing at at the moment, he is one of the best players in the world — and I think he can and will get even better," said Totti.
“I know him well, he is a good friend and wants to keep improving, to keep getting better as a player.
“He does all the right things, he trains hard, he works hard, he listens to the coaches – that's why, as good as he is playing at the moment, I think maybe there is even one more level in him."
And Totti believes Jurgen Klopp's side could be crowned European champions for the sixth time.
“He is one of those players who can make the difference in the big games," added Totti. “That is why Liverpool cannot be ruled out of winning the Champions League.
“There are more complete teams in the competition – but when you have a player like him, you start to believe anything is possible."