Lippi had been criticised for ignoring Cassano this season - that is until the striker fell out with Samp coach Gigi del Neri.
He said: "It never even went through my head to shout it aloud or say I was right on the Cassano issue. That's not something I think about.
"There are already 16 or 17 players certain to be in the World Cup squad. Then I have another six to work on so I can complete the 23-man list.
"I have four months left to make the decision. My choices will be dictated by the fitness levels at that moment and who is in best shape will come along.
"For 23 roles there are 35 who are playing well and so someone's got to be left out. I don't do names, just let me do my job and based on results you can give your opinion."