Former Roma and Italy goalkeeper Paolo Conti has claimed that Alisson is currently 'the best stopper in the world'.
Manchester United's David de Gea and Bayern Munich's Manuel Neuer are widely recognised as the two leading goalkeepers in world football.
Alisson's form for Roma, however, has led to claims that Liverpool and Real Madrid are interested in signing the 25-year-old.
Conti, who turned out for Roma between 1973 and 1980, has paid tribute to the qualities of the Brazil international.
"Alisson is certainly the best goalkeeper in the world right now," Conti told Radio Centro Suono Sport. "It's almost impossible to set a market value for him, seeing the crazy figures that are flying around at the moment.
"I said Alisson was excellent a long while back and now he is simply priceless. He has great intelligence and anticipates the moves of the opposition team. He doesn't need to make spectacular saves, because his positioning is so good."
Alisson has kept 17 clean sheets in 37 appearances for Roma during the 2017-18 campaign.