Jankto, 22, made 36 Serie A appearances for the Zebrette last season, scoring four goals from deep.
Jankto had previously been linked with Arsenal, but it now seems he will act as the replacement for Torreira, who is a reported target for Unai Emery in North London.
Torreira's father told Teledoce recently: "It's a big change [going to England] and we don't want to think about it yet because we're scared.
"The truth is it's tough to manage the language, adapt to the [London] society and customs and at the same time not lose ours.
"But there's a whole programme getting readied for Lucas."