A week ago in the Sicilian derby at Catania, the Rosaneri were greeted by a stadium full of fans holding up signs bearing the letter B, a taunt which Sannino hopes will motivate his side to raise their game sufficiently to beat the Nerazzurri.
"That is what we remember of the derby in Catania and that has got to accompany us and remind us of the situation we are in," he said.
"A professor asked me what percentage I would give to us staying up. I'm no expert on percentages, but certainly this is a vitally important game.
"The only certainty is that Inter are superior to us and, to beat them, we are going to have to put that little bit more desire into the game which will be required to win it."
Thanks to a last-gasp equaliser by Josip Ilicic at the Stadio Massimino last weekend, the Rosaneri are four games unbeaten and only a point from safety.
However, with games at Juventus and Fiorentina and at home to Udinese - all clubs from the top half of the table - to come, Sannino would have preferred to have more points on the table.
"In these last five games, we've got to try to do everything which we failed to do earlier," he said.
"I'm only sorry that we didn't get these points before, but the lads have understood what I want and we will try to get as many as we can."
Inter coach Andrea Stramaccioni believes Palermo are now playing to their true potential and that their current league position is irrelevant.
"This is their real value," he said. "I am convinced that they can hurt anybody, especially at home.
"They are also going to be pushed by their own fans. This is an important game for them, but it's important for us too.
"It is going to be a combative and lively game from the very beginning."
Stramaccioni is still without a long list of injured players, which includes Diego Milito, Antonio Cassano, Rodrigo Palacio, Walter Gargano, Walter Samuel, Esteban Cambiasso, Dejan Stankovic and Gabi Mudingayi.
"It annoys me to hear about them being decimated by injuries," said Sannino. "The players we face are still Inter players."