The Catalan club have first refusal on the youngster and may look to exercise their option on him.
Exciting Fluminense forward Gerson has impressed at his club and for the Brazilian Under-20 team since his emergence last December, and Barca have reportedly seen enough to warrant his purchase.
Valued at £5 million, the tricky, pacey midfielder can operate in a deeper central role or from the right cutting in, onto his favoured left foot.
Barcelona's transfer technical committee member Ariedo Braida is believed to be working on finalising a deal this week, ending speculation of a possible Premier League move for the 18-year old.
A report in the Catalan daily Sport, via Talksport, suggests Barca will opt to exercise their first refusal on Gerson in the coming days.
As with any Barcelona signing this summer, fans will have to wait until 2016 - when their transfer ban is lifted - to watch Gerson grace the Camp Nou pitch.
His agent is quoted as saying:
"Both Gerson and I want Fluminense and Barcelona to reach a definitive agreement over the transfer."
With Gerson’s switch to Barcelona seemingly a foregone conclusion, Chelsea and City may have to look elsewhere knowing, on this occasion, the lure of the European Champions has proven too strong.