A report in the Spanish language version of OneFootball on Monday said that the Blues are thinking of launching a bid to activate the 20-year-old's €15m release clause, a claim that was backed up by Sebastián Srur of Argentine outlet Radio Continental who tweeted that there could soon be news along these lines.
That was followed by further reporting by Srur on Friday (17 March) that Sosa's agent will fly to England within the next week to conclude the £13.5m move which would see the midfielder follow Ramiro Funes Mori from River Plate to Goodison Park.
Sosa, who signed his first contract with the Buenos Aires club last year, will be a member of the Argentina team that will feature in the U20 World Cup that kicks off in Poland in 10 days' time and his move to Merseyside will be announced after the tournament.
The player, who would struggle to get a work permit to play in England straight away, was asked about the speculation and while he admitted that he was flattered to be coveted by a club like Everton, for now his focus is on the U20 World Cup.
Marcel Brands is said to have travelled to Chile to scout at the South American U20 Championships in January and February. Argentina finished as runners-up and Sosa was named in the team of the tournament.
Updates On 23 May, the Liverpool Echo reported that while Everton have been keeping tabs on Sosa, they don't have any imminent plans to sign him and would likely revisit their interest in January.
On 28 May, however, TyC Sports were still maintaining that Sosa's representative would be flying to Merseyside to conclude a deal for his client within the next week.