The Brazil international, who is currently representing his country at the Olympic Games on home soil, has attracted interest from teams in Europe after impressing for the Peixe in the last two seasons.
Gabriel, dubbed 'Gabigol' in his homeland, scored 15 goals in the past 18 months to help the Sao Paulo giants win back-to-back championship titles and he was named in the Campeonato Paulista Team of the Year for 2016.
Roma revealed last month that the 19-year-old forward was being monitored by Italian champions Juventus and has now disclosed an offer from Serie A rivals Inter.
"I can confirm that Santos have received an offer from Inter and now we're all waiting for a definite decision to be taken by the player and his family," he told fcinter1908.
"It will depend a lot on them, so if they give their consent, we will start to conclude negotiations with Inter. It will probably be [after the Olympics]. We're all waiting."