The former Rossoneri star left Milan to join Real Madrid for 68.5million euros in 2009 but Galliani has spent the last two transfer windows trying to re-sign the Brazilian, who has steadily fallen down the pecking order in the Spanish capital.
Attempts to recruit the 31-year-old on an expensive loan deal in January were abandoned when Manchester City striker Mario Balotelli became available for 20m euros and, according to Galliani, money remains tight at San Siro.
He told legaseriea.it: "Kaka has very high wages and is now 31, so I can rule out any move to Milan."
Balotelli's arrival signalled a change of tactics at Milan with Stephan El Shaarawy flanking his Italy team-mate alongside M'Baye Niang. The system yielded a third-placed finish but president Silvio Berlusconi has reportedly asked coach Massimiliano Allegri to use a deep-lying forward - or "trequartista" - behind two strikers for the 2013-14 campaign.
And Galliani insists Milan are ready to employ 21-year-old midfielder Riccardo Saponara - a January signing from Empoli - in that role after being priced out of any move for 2007 Ballon d'Or winner Kaka.
"There are no restrictions on using a trequartista," he added. "That change in the team should be a natural evolution and that's why we bought Saponara."