Inter sporting director Piero Ausilio dismissed the idea of Perisic moving to the Premier League side on Wednesday, claiming the move is "not happening" .
Goal understands Inter coach Luciano Spalletti has tried to convince the Croatia international to stay, but the winger has made his decision to leave and it is increasingly likely he will head to Old Trafford.
Goal reported in June that Perisic has given his agent, Fali Ramadani, orders to force a move away from the Nerazzurri, and he looks set to get his wish.
Inter's director of football Walter Sabatini has since revealed the club are open to a potential swap deal with the Red Devils.
"Manchester United are interested in Perisic," he said. "We could also accept other players in exchange of him."
Perisic has spent two seasons with Inter after joining from Wolfsburg. The 28-year-old has played 70 games in Serie A, scoring 18 times.
INTER-MAN UTD SWAP OPTIONS
Inter are interested in United pair Matteo Darmian and Anthony Martial, Goal understands.
And although Mourinho is a fan of his ability to operate in both full-back positions, Inter can offer Darmian more first-team football, which is crucial ahead of the upcoming 2018 World Cup.
However, Inter would find it more difficult to land Martial in any swap deal which would take Perisic to United.
While Martial - like Darmian - is also not a guaranteed starter under Mourinho, the Frenchman's value is at least the same, if not more, than Perisic's current €45m asking price.
Martial, who scored eight goals in all competitions for United last term, would be a good fit into Spalletti's typical 4-2-3-1 system.
But while Mourinho would prefer to keep the young forward, he could be tempted to swap him if he needs to in order to close the Perisic deal.