Mario spent the latter half of last season on loan with West Ham and impressed during his time in London, making 14 appearances and scoring twice. They are believed to be interested in finalising a permanent deal for Mario, but face competition from a whole host of Premier League clubs.
Italian outlet Stadiosport are reporting that both Southampton and Bournemouth have entered the race for Mario, but there are multiple reports from other Italian outlets about the interest from various Premier League clubs.
Gazza Mercato mention Everton as one of the interested parties, whilst Tuttosport also claim that Mario could be set to join Tottenham in a deal which would see Belgian midfielder Mousa Dembele swap White Hart Lane for San Siro.
Southampton and Bournemouth are believed to be leading the race for the Portuguese international, with Stadiosport reporting that concrete offers from the two clubs are expected in the coming days.
Inter are believed to be interested in selling Mario in order to raise funds to appease UEFA's Financial Fair Play regulations. The 25-year-old joined Inter in 2016 for around £38m, but it is believed that the Italian club are prepared to accept a lower fee in order to finalise a deal.
Southampton could be in the market to replace attacking midfielder Dusan Tadic, who has recently left the club to join Eredivisie side Ajax.
It is believed that West Ham are interested in securing a permanent deal for the Portuguese midfielder, but with Southampton, Bournemouth, Everton and Tottenham all interested, the race to sign Joao Mario could well be a long one.