Cassano has been convinced to stay by President Riccardo Garrone and the fans, who jeered Del Neri during yesterday's 2-0 win over Atalanta.
"I don't want to talk about Cassano," insisted the Coach after the final whistle.
"I am very bitter about the way this situation has gone, yes. Let's just say it's my own business why.
"I would prefer to discuss those who actually played today and won the match. For the last two weeks we've talked about nothing else."
Since dropping Cassano, the Blucerchiati have won two on the trot and Del Neri made no secret of the fact he prefers the team without its star player.
"The lad is part of the Sampdoria squad and we want him to help us reach our objectives in the final sprint of the season.
"At this moment I have made my choices and they need to be respected. Right now I need more aggression from the team.
"Without Cassano we lose in terms of quality, but gain in aggression. Keeping him on the bench is pointless."