With a Wembley meeting with Sky Bet League One club Sheffield United awaiting Hull, all of those pushing for a starting berth will be hoping that they get the nod on Sunday.
The ineligibility of January signings Nikica Jelavic and Shane Long has opened things up in the attacking third, but there will inevitably be a number of players left disappointed at being overlooked.
Bruce is not looking forward to delivering that news and will look to leave it as long as possible before piecing together his matchday squad.
He said in the Hull Daily Mail: "It's a semi-final and I'm going to disappoint some people. Everyone wants to play and rightfully so, it's Wembley.
"That's when your job becomes horrible and nasty because you've got to let people down.
"I've got 25 players and I can pick 11, so I'm going to have more people disappointed than happy.
"George Boyd, for example, has made a huge contribution and he has a great chance but it's not easy."
Regardless of who makes the team sheet on Sunday, Bruce insists no-one in the Hull camp will be taking third-tier opponents lightly - with the Blades having already claimed the Premier League scalps of Aston Villa and Fulham during their run to the last four.
Bruce added: "You look at what Sheffield United have done and nothing's a given at Wembley.
"I remember my first one (with Manchester United in 1990) when we were supposed to trounce Oldham and we got away with a 3-3 draw.
"A semi-final is a semi-final. There's nerves, edginess, you need a bit of luck and the bounce of the ball.
"We may never get a better chance of getting to an FA Cup final, but Sheffield United will be thinking exactly the same thing.
"We've got to perform on the day and that's the key. No matter what division you're in, you have to perform on the day."