Boban, reacting to this week's comments from Kaka that violence at Italian stadiums could drive him away from Serie A, said: "For several months, in his own way, timidly, he's been pushing the idea of changing scenes.
"Many small clues have been offered and suggestions have pointed towards Spain. Is it only harmless flirting or is Kaka really betraying the love the Rossonero show for him?"
In his column for Gazzetta dello Sport, Boban also wrote: "His hints about being available to extend his contract, saying that it all depends on the desire of Milan appears to me to be increasingly misplaced. Then I wonder, but hasn't his contract not already been retouched?
"Being the true symbol of a club is a recognition of the human and professional values of a player. And one of these is loyalty.
"Kaka, although time is running out, you have the chance to choose. If you do not want to stay in Milan, you should find a more elegant way of expressing yourself. Perhaps with a bit of clarity."