A draw would earn the Viola a top-five finish while victory would keep their hopes alive of catching AC Milan and qualifying for the Champions League should results permit.
With those objectives still to play for, they cannot afford to worry about their opponents' plight.
Defeat for Palermo would see them relegated to Serie B while a draw may not be enough to keep their survival hopes alive either.
"We have not achieved anything yet," said Montella after his side's 1-0 win at Siena in midweek.
"Fourth place still needs consolidating and we want to do that on Sunday in front of our own fans.
"Our season has been full of positives with a few mistakes. We can't change anything now and I have no regrets.
"I want to consolidate fourth place."
Striker Luca Toni, whose contract may not be renewed in the summer, has not given up hope of dislodging Milan as he prepares for what may be his last game at the Stadio Artemio Franchi tomorrow.
"Our chances are small, but we've got to believe in them," he said at a press conference.
"Fiorentina are heading in the right direction. I don't know if I will be part of it next season, we'll have to wait, but I want to thank everybody in Florence for the way I have been treated here."
Palermo president Maurizio Zamparini has already accepted his side's destiny, saying it is not a tragedy to go down.
"We're pretty much resigned to it," he told Radio 24. "It's an opportunity to clean things up within the club in Serie B.
"We will change our budget so it is not a tragedy.
"You get years like this, life is made of highs and lows and there are times when a striker scores with his backside and others when it goes wide.
"My team is good enough for 50-53 points, we just made some stupid mistakes."