The atmosphere at Goodison tomorrow is sure to be white-hot with no quarter given or asked for.
But Everton's Aussie warrior Cahill is confident it will be the Blue half of the city who will emerge with the bragging rights.
He admitted: "Defeat is just unthinkable.
"But there's so much spirit in this team. You look round the dressing room and think there's too much quality to accept some of the results we have had, regardless of how unlucky we've been.
"I am confident the players can put on a performance. I believe in this squad, it's probably the best we have ever had, and after getting our first win at Birmingham, another here would really kickstart our season."