The 22-year-old has been impressing in Portugal this season and has caught the eye of a number of clubs.
Chelsea have been linked with the centre-back, as have AC Milan and Napoli in Italy.
However, according to Calciomercato, it is Everton who are ready to follow up their interest with a concrete bid.
Toffees boss Ronald Koeman is set on revamping his defence at Goodison Park after selling John Stones to Manchester City for £50m in the summer.
Semedo, given his age, is viewed as an ideal long-term signing but Sporting are reluctant to enter negotiations at this stage.