The Brazil forward’s future has been subject of much speculation recently and Galliani admits there has been interest from an unnamed club, thought to be Corinthians.
“An offer has arrived for Pato,” Galliani told Milan Channel.
“Basically, in defence and midfield we will not be signing anyone. If Pato and Robinho remain, or if only one leaves, then we won’t bring in any replacements.
“We believe the right number of strikers to have is five, because if two new ones arrive, then there won’t be space for M’Baye Niang.”
The Rossoneri chief added that he is trying his best to keep Robinho at the club, and revealed it is the player's wife and children who want to leave Milan and not the Brazilian himself.
“We’re doing everything to keep hold of Robinho, although I am not certain that we’ll succeed," he continued.
“Robinho is happy to stay here and has a wonderful rapport with the coach and team, but his wife and children want the beaches of Santos.
“I hope to convince him to stay here, though he is asking to leave Milan and go back to his homeland.”
Milan are currently seventh in Serie A after taking 27 points from 17 games.