Richarlison was undergoing a medical with Everton on Monday ahead of his proposed transfer from Watford.
It emerged last week that Everton were closing in on signing the Brazilian forward, who played for Toffees boss Marco Silva at Vicarage Road last season.
And it is understood Richarlison was at the club's Finch Farm training ground having a medical on Monday morning as they looked to finalise a deal worth up to €45m.
The 21-year-old joined Watford, where Silva was newly-installed as manager, from Fluminense last summer.
He scored five times in his opening 12 Premier League matches, but did not find the net again for the rest of the campaign.
Everton and Watford have had a somewhat testing relationship, with the Merseyside outfit seeing an initial approach for Silva rebuffed after they sacked Ronald Koeman in October last year.
Watford subsequently decided to dispense with Silva's services in January, saying the "unwarranted approach" had been the "catalyst", leading to "a significant deterioration in both focus and results".
Everton named Sam Allardyce as Koeman's successor, and after he was then sacked at the end of the season, Silva was appointed on May 31.