The teenage right-back did not hold back against the world's most expensive player, despite PSG running out 5-0 winners at Celtic Park, so much so that Neymar refused to shake his hand at the end of the match.
Scouts from Everton are understood to have been in Paisley as Hoops kid Ralston again impressed in Scotland Under-21s' 2-0 win over Holland last week.
The Paris Saint-Germain icon has been criticised for appearing to snub Ralston after the final whistle, refusing to give his shirt to the 18-year-old.
He said at the time: "It was not a big deal. I won't dwell on that too much", the defender said after the match.
Specifically, Neymar agreed to donate his shirt to the Marina Dalglish Appeal, the cancer foundation ran by the wife of Celtic legend, Kenneth...
Ralston is contracted to Celtic until 2019 but it looks as if the Scottish champions will have a struggle to keep the teenager if he carries on his current rate of progress.
The Toffees signed Cuco Martina to boost their right back options in the absence of Seamus Coleman, but the Curacao global has yet to impress fans at Goodison Park.
Coleman continues his recovery from a broken leg while Martina has come in for criticism from some quarters for his performances since signing from Southampton.