Kaka said prior to Milan's 3-0 win over Chievo on Saturday that he would like to play in the MLS if he is to leave San Siro for a second time in his career.
The Brazilian made his 300th appearance for the club against Chievo, which he marked with a double before insisting he is in "no hurry" to end his second spell with the club.
However, Galliani confirmed that the 31-year-old has a clause in his contract allowing him to depart if Milan - who are ninth in Serie A - fail to qualify for the UEFA Champions League.
"It's very simple. Kaka has a contract until June 30 2015," Galliani told Sky Sport Italia.
"But if we don't qualify for the Champions League then he has a clause allowing him to leave. We will discuss it, but I firmly believe he will stay."
And Orlando, who are set to join the MLS as an expansion franchise in 2015, suggested that they are the favourites to secure Kaka's signature should he leave Milan.
The club's co-owner Phil Rawlins attached a link to a report on Kaka's potential move to a tweet which read: "We're ready when you are Ricardo #MLS21."
Orlando - top of the USL Pro with just one defeat - are partly owned by Brazilian Flavio Augusto da Silva and were confirmed as an expansion franchise in November last year.
