Both players have been linked with a return to Brazil, with Galliani confirming recently that a bid had been received from an unnamed club for Pato.
Corinthians are thought to be interested in the 23-year-old while Robinho is keen to return to Santos, the club where he started his professional career.
And Galliani says he will be travelling to Brazil for negotiations over transfers for the pair after they both asked to be allowed to move.
"I planned my trip to Brazil some months ago, it will be only about work, I'm not going on vacation," Galliani said.
"We have two negotiations going on, both Pato and Robinho asked to leave Milan, and I know what will happen if they leave the club."
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