Luiz and Cahill have both been struggling with hamstring injuries, but Chelsea manager Roberto Di Matteo had been hopeful they could recover in time for the showpiece at Wembley.
It appears, however, the pair have lost their battle to make the final, meaning they will likely now focus on being available for selection when the Blues take on Bayern Munich in the Champions League final on May 19.
Kings for a Day - Football's Giant Killers - focuses on the unique David vs. Goliath aspect of The FA Cup. Using a mixture of behind the scenes footage from this year's competition, plus archive material from previous years, the film provides a unique insight into the psyche of the underdog which is so key to the competition. The show, to be broadcast on FA Cup Final day as part of ESPN's build-up to its live coverage of that match, features interviews with the likes of FA Cup giantkillers Ronnie Radford and Vinnie Jones plus legendary FA Cup commentator John Motson.