The Dutchman is among 30-names on the prize's shortlist.
"If you give the Ballon d'Or to the best player of this generation then you should give it always to Lionel Messi. That's how it is," he said.
"But if you give it to the best player of last season, then it was Virgil van Dijk.
"I don't know exactly how it will work but that is how I see it.
"The best player of all? That's Lionel. Best player of last season? That's Virgil. We will see."