The winger, 30, has been linked with a return to his homeland for the past few transfer windows and interest from Atletico Mineiro, Flamengo and Cruzeiro has all been widely reported in recent weeks.
Although Rodrigues played down the deal being 100 per cent complete, he has revealed that Robinho has lowered his wage demands - initially a sticking point concerning a move - in order to force through a return to his old club.
"Although many Italian outlets have taken for granted the return of Robinho, I can confirm to you that negotiations are progressing well," the club chief told Santos TV.
"We are doing everything possible to sign the player and he has also lowered his initial demands.
"We have huge hope that the transfer will be complete soon. We hope to give the fans this gift as soon as possible."
Santos look set to see off a rival bid from fellow Brazilian club Flamengo, who confirmed interest in bringing the ex-Real Madrid man on board this year, and new MLS franchise Orlando City, who were linked with a potential bid earlier this summer to reunite the player with Kaka.
Robinho has been with Milan since 2010 after joining for £14m from Manchester City.