The French midfielder was linked with moves away from Old Trafford to Juve and Real Madrid in the summer, just three years after he joined the Red Devils in a then world record £89m deal.
Pogba has made just five appearances for Ole Gunnar Solskjaer's United this season as a result of injury.
Ribalta, who is now sporting director at Zenit St Petersburg, told Tuttosport that Juventus are likely to make another move for the United academy product at some point.
When asked about the likelihood of Maurizio Sarri's side signing one of Pogba, Kylian Mbappe, Erling Haaland and Joao Felix, Ribalta said: "None of the four looks simple to me, but I would bet a pizza with a friend on Pogba's return.
"Without Champions [League], Paul is destined to leave Manchester United."
Solskjaer indicated earlier this week that the midfielder is likely to be return to first team action against Sheffield United following the upcoming international break. body check tags ::